This will be your most valuable link once you get your project started.
And the most favored frontends are MaLa and AtomicFE. The differences between the two are pretty subtle, and they both handle other emulators.
As far as your monitor, I think that depends on whether your going to use a real arcade cabinet, or make one. Also, do you plan to play actual arcade boards? You'd want an arcade monitor and a JPAC. If you just want to run a PC it'd probably be easier to use a PC monitor.
www.ultimarc.com has plenty of adapters and things, like the JPAC.