Hello, Tony,
Would you mind a light that uses somewhat difficult to find batteries? A lot of higher-end lights use Lithium CR123s, which are affordably priced on the net, but cost up to 10 dollars each at retail stores. If you wouldn't mind buying your cells from Internet sources, then there are quite a few lights available to you that I believe would fulfill your needs. For example, the Streamlight TL-3 uses 3 of the aforementioned cells, outputs just above your Surge, and gives around 1 hour of battery life. The Surefire G2 runs on 2 cells, has around half the brightness, and runtime similar to the TL-3. The G2 costs around 35 dollars, and the bulb costs around 17. Streamlight's TL-3 will set you back around 60 dollars, but the bulb is only 5. Their TL-2 might also be worth a look.
If alkaline cells are important to you, I would recommend either the Streamlight ProPoly Luxeon 4AA, or the Fenix L2T. Both of these are LED lights, and never need bulb replacements. The 4AA runs on 4 AA cells (surprise?) and the L2T runs on two. The L2T is a 2AA version of the L1T mentioned by CFU, and also has 2 brightness levels. Set to low brightness, it provides ample light for navigation, and runs just around forever. It runs for around 1.5 or 2.5 hours, depending on whether you use it with alkalines or NiMH cells. The ProPoly 4AA will give you an astounding 4 to 5 hours of output. Neither of these lights are as bright as your Surge, but the output from them is regulated and essentially non-dimming, unlike your current light, which spends most of its time somewhere between 25 and 50 percent of its maximum brightness. The Streamlight ProPoly is also very durable. It will costs you around 30 dollars. The Fenix runs around 45.
The Nuwai 301X-5 would seem to be a good choice for an LED light that runs on CR123 cells. It is very bright, and runs for around 2 hours on 2 cells. It is priced at around 65 dollars.
I agree with CFU that the Fenix E1 would make an exceptional backup light.
I would recommend that you take a look around some review sites, such as flashlightreviews.com. This site tends to be quite informative, and an excellent buying guide.
I wish you the best of luck in your search, and with your new light.
Regards,
Nima