Older versions of MAME will run fine on that machine, at least in DOS.  I'd recommend using MAME 0.55 - 0.78 on a machine like that.  However, if you're planning to use Windows so you'll have USB support, I'd stick to the lower end of the MAME version range I gave.
As for front ends, I like AdvanceMenu in DOS, but it's a pain to configure.  Another good but simple one is GameLauncher.  In Windows, I like how customizable Dragon King is, but I'm not sure it would run well on that PC.  MameWAH is the popular choice, but I've yet to figure out why.