AtomicFe can run on your configuration.
Not "out of the box", you will have to change the default layout which require more power due to animation. (but you can try it out of the box , to see how it perfoms on your config)
but you can perfectly scale Atomic to run on your configuration. It support also very old version of MAME.
XP Pro is good for you configuration too, but of course you have to stop all unneeded services. Avoid Lite XP version, that are not very good. The only interrest of these version are that are use less disk space, except that you can have same performence with a full Xp version and you will have less problem (in Lite version some file are missing that can cause problem when you install some emulator, driver, codec ..etc...)