Here's my opinion on the matter.
Regardless of what you end up with, I think you'll find it indespensible to have either 2 lights, or one light with at least 2 levels of output. The thing is, having a very bright light is fun, and useful at times, but at other times, it's way too much light (blinding you) or more than you need (sucks batteries). And you might also find it prudent to only use lights that can use rechargable batteries. The cheapest CR123A powered flashlight isn't so cheap if you have to feed it batteries all the time.
For a single light, my favorites are the McLux III PD or the HDS EDC series. However these can make Surefires look cheap, so we can probably just skip over them. I like them because unlike many other lights, they have pocket clips.
IMO, the best all-around "personal" flashlight (meaning it's not a 2 battery "tactical" light) is the Fire-Fly III by DSpeck (available in the Manufacturer's section). Compared to every other 123A sized light, it's tiny (2.75" long for the keychain body--the pocket body is even shorter), but packs a hell of a punch. The circuit has 5 different operating modes which give you a choice of 2-3 output levels (fully adjustable) and strobe modes. Put a lanyard on it and it disappears in your pocket. Best of all it's designed to use rechargable lithium ion batteries, so you can run it for free after the initial purchase. With 2 batteries and a charger, it'll be shipped to your door for $136. That's about the price of a Surefire L1, but half the size and with more usability (and the SF can't use rechargables).
If you go with 2 lights, you could try a Nuwai Q3 (kinda a budget Surefire E1E) for your eye-melter. It can run on rechargable 123As, but runtime is pretty short. The upcomming Jetbeam Jet-1 looks to be a wonderfully versitile platform. It'll run on a regular AA like a Fenix L1P, but it will also run on a 14500 lithium ion rechargable (think of it as a AA sized R123A) for eye-melting goodness. The head can be swapped to a 123A body (and use either regular lithiums or rechargable li-ions) in a smaller package (twisty switch isntead of a clicky). However the initial run is sold out, and the production runs will be a while.
Even something like the Fenix L1P is a great light. Not eye-melting bright, but inexpensive, very high quality, and runs great on NiMH rechargables.
Whichever "main" light you get, compliment it with a keychain light like the Arc AAA or even a Photon micro light. I love keychain lights, because since you always have your keys, you'll always have a flashlight. My favorite keychain light right now is the Jil Intelli. It has the same circuit as the Fire-Fly III, but runs on a CR2 battery (also available in rechargables). It's tiny (barely 2" long) but damn bright for its size (damn bright for flashlights 2-3X its size). bright enough that it can replace most larger flashlights for normal every-day use unless you require a brighter light with more throw. And even if you get all the flashlight you need in a single one, it's always good to have a Photon (or even a Fauxton) on your keychain. They're extremely small and disappear on your keychain, and you'll always have it even if you forgot your "real" flashlight (or its batteries died).
As nice as the Surefire A2 is, I'm really not sure it'd be a light good for your applications. It's fairly long (think of it as a fat minimag), and needs 2 regular lithium ion batteries (expensive). SOme people run rechargables with it, but you'll only get about 30 minutes runtime with the main lamp. I would venture to say that it's more flashlight than you need. I would also venture to say that if you had both an A2 and a Fire-Fly III, you'd be walking out the door with the FF3 much more often, because the A2 will seem excessively large and too expensive to run. I see the A2 as more of a "professional" light, or one to keep by the front/back door for "bump in the night" situations, or to keep in the glove compartment. Also, if the size of the A2 means you might leave it behind once in a while, it might get stolen. The smaller the light, the easier it is to keep on your person.
The reason I'm so enamoured with rechargable batteries isn't just due to cost (although I suppose it is by extension), it's because I use my flashlights more often. I don't have to worry about the cost and draining the batteries playing around with them at my desk. And most importantly, I don't have to worry about how much juice is left. Use a flashlight off and on for a few days/weeks, and you'll have no idea how much life is left (especially if you use a light with regulation that doesn't dim when the batteries drain). Is it half drained? Is there only 10 minutes left? Should I put a new one in and waste what's left of the old one? Should I carry a spare? With a rechargable, you don't have to worry about this. Just charge it up. I know my McLux III PD runs for an hour at max. If I don't know how long I've used it, I just pull a fresh one off the charger and charge the old one. When I was using regular lithiums in my Surefire L2, I was always apprehensive about using it, even on low mode (and it lasts a longass time on low). Even if I needed it, I didn't like using the high mode because I knew it was draining my batteries. I don't worry about using high mode at all any more (all I have is single-cell rechargable based flashlights; I sold the L2) unless I'm taking a long walk somewhere or something.
I hope this longass post helps you make a choice.
on rechargeables
Relax and don't think so much. Trust me on this, before all is said and done you will have bought many flashlights and have thoroughly enjoyed yourself along the way. So chill out and just buy one or two of the inexpensive lights for now and along the way you can go for the gusto.
