I just made my arcade simply because I had a modded xbox. Went out to the local buy sell trade game stop and bought 4 used 3rd party xbox controllers, stripped them down, soldered leads to up, down, right, left, x, y, a, b, back, start, white, black, and on one of the controllers R and L so that I could navigate quickly through all the roms. For fighting games: with first and second player I soldered all the points listed above and for 3rd and 4th player I simply just used the d pad + abxy + start /back (for simple beatumup games). I really dont think getting the lik sang keyboard mouse convertor would work out that great, Im not sure if they've even come out yet but while lik sang has some great ideas and makes cool things happen, their support for things such as n64 to usb converter surely didnt work very well at the very beginning. I could be completely mistaken though on your preference partially because I think the xbox games get pretty old pretty quickly and anything that you cant use a dpad on (unlike MK: Deception) isnt really worth playing. I just dont see how standing up to play a complicated controls game like halo on a big ass control panel. If you're interested in going the route I went and just picking up some crappy 3rd party xbox controllers I'd be happy to explain whats needed to make it all work. I finally got my arcade finished about a week ago and everyone seems to be in love with that old school gaming feeling plus being able to play newer games like the port of Marvel Vs Capcom 2, MK Deception, and hopefully soon all n64 games will work flawlessly.