eds1275,
I don't use MaLa, so I can't comment what it can do for you, but you have options many options available to you...
From BobA's post, it sounds like Maximus Arcade makes use of some kind of "wrapper" software to make launching exiting games cleaner and consistent across multiple emulators. HyperSpin has something similar, an application called HyperLaunch. I know that at one time, I was finding a goldmine of customizable wrappers over in the GameEx forum, for every kind of emulator under the sun. Not to mention some oldie-but-goodie sites like Talking Octopus, which has emulators which have been modified to be more cab-controller friendly:
http://webpages.charter.net/rbecker5/emulators.html ... an oldie but a goodie.
Or Howard Casto's generic wrappers:
http://dragonking.arcadecontrols.com/static.php?page=wrapperdownload ... another oldie but goodie.
But my suggestion to you is to simply use joystick encoder software, like JoyToKey. There is a newer more popular program that people use now, but I can't think of the name of it right now. Anyway, the point is to run a program to take input from your USB Xbox360 controller, and convert your button presses and joystick motions into keyboard codes... after all, nearly all of the emulators out there can be controlled purely with a keyboard. You can use JoyToKey to map your controller to the default MAME keycodes, then many emulators will work right out of the box. For the others, either you customize the controls within the emulator itself, or you get fancy and launch JoyToKey voa command-line to change the mappings on a per-emulator basis.
So again, there are many options available to you, it's just a matter of figuring out what's going to work for you.
-EVEGames