Mag 2D mod parts selection help

I'm planning to do my first 2D Maglite mod. I'd like to eventually end up with one Seoul P7 with a multi-mode driver running off a pair of D size LI batteries but I'm planning to start much simpler and work my way up. Initially I'm looking at:

3x AA NiMH in series for 3.6V
P7
Direct Drive
P7 specific heatsink from H22A https://www.candlepowerforums.com/threads/203235&highlight=heatsink

I'd probably then migrate to 6x AA and a simple driver circuit as I learn what I'm doing. I don't plan on going over 1A drive current for quite a while.

My questions are:
* Given that I'm staying under 1A drive current for the near future would there be a better choice than a P7. They are pretty expensive ($20-$30) and I can get Cree XRE-Q5s, Cree P4s or Seoul "Z-power" http://www.dealextreme.com/details.dx/sku.1445
for around $5 each but I have no idea how efficient these emitters are or how well each would work with the Mag reflector. Any advice?

* Some of the emitters on dx come mounted to a circuit board for easier soldering and some don't. Any recommendations?

* If I end up using few mm worth of spacer material (aluminum washer?) to make whatever emitter I choose work with the P7 specific heatsink rather than dremmeling it flat will it screw up the focus too badly with the stock Mag reflector?

Thanks

Ray

This thread could have some ideas for you.

All those emitters are about the same efficiency. The P7 can just handle more current than most (since it's basically four Seoul P4s in parallel).

The Seoul P4 works well with the stock Mag reflector. Get a bare one, not star-mounted, and just stick it to the heatsink with thermal epoxy (like Arctic Alumina).

I'm not really following you with that bit about the Dremeling and spacers, in regards to what is being Dremeled and such, and why.

To make a stock Mag reflector work with a DHS, just cut the cam off. It's focused by loosening and tightening the head - it just takes a lot more turning than the cammed method does.