You will need:
-A super gun ($100-$400) depending on quality and capabilities.
with s-video out put at least.
-A jamma harness ($20-50)
-2 controllers (any style neo controller or 3rd party/custom arcade sticks)
You should probabley get a harness with a 6 button kicker so you can play jamma boards and other arcade pcbs with it.
If you are only interested in playing neo MVS stuff you should just get a consolized MVS system ($200-$500)
I dont know too much about MVS stuff but this should help.
Search the 24-bit and Tech forums here and you should be able to find a ton of info.