MAME32 for Girlcab. Just wanted something easy for the primary users and MAME32 is pretty straight-forward.
I'll be using a different front end for MY cab, tho. One that can run MAME plus 2600, 5200, NES, Coleco, etc. emulators. Haven't researched enough yet to decide. . .
I would suggest Atomic for your cab - with all the plug and play modules you've got the emulators already setup to work...
Unless you are using a 49 way.

EDIT Dec 28th 2006-
Atomic Rocks if you are using 49 ways, LED Wiz, and an AVGA. Plus if you are using an LEDWiz, you do not have to buy a special chip to use it, it works right out of the bubble wrap. If you have access to some graphics software, you can make the killer FE interface. If you have video editing or animation software, it just gets sicker. It can be as easy of as difficult as you decide to make it. You can dip your toe in and test the water, then when you are feeling a little more brave you can do a more feature rich set up.

BTW, was using MAMEWah and PowerMAME32 prior to AFE. PM32 was fine on a computer monitor, but is hell on the eyes at 640 x 480 on an arcade monitor. MAMEWah was great I just wanted the ability for 49 ways and LEDWiz without having to have an engineering degree to get there.