For a processor that slow, I'd run MAME version 106.
You can download older versions of MAME on the official MAME website.
http://www.mamedev.org/oldrel.htmlI can't tell you where to get the roms, but search for a version 106 romset.
The reason people stick with this particular version for slower computers is that there was a major overhaul in version 107 that resulted in more demanding minimum specs. Because a lot of people stick with this version, you can find romsets out there for it.
The standard MAME build doesn't have a user interface (no nice menus or game selection screens).
They added a bad game selection screen just to keep people who didn't understand the program from complaining that nothing happened when they clicked the exe.
You can either search for an old user interface derivative of MAME (MAMEUI, MAME21), or use a front end.
If you choose Mala as a front end, UncleT has step by step instructions here:
http://forum.arcadecontrols.com/index.php/topic,56010.0.htmlAfter being in this hobby for years, I do things differently, but those instructions are what got me started.