Most arcade boards, well alot anyway output in RGB, so if you plan on playing on a TV you need an encoder, this is the most expensive part in the puzzle.
The most popular one out now is the Jrok
Check these pages out, pretty much everything you need to know:
http://www.digitpres...es/arc00093.htm
http://cps2shock.ret....com/jamma.html
http://www.sgrepository.com/
There are others but those are pretty specific for what I believe you are wanting to do. Also a few places make & sell these things prebuilt with controllers for around $300
like:
http://www.massystem.../SuperNova.html
&
http://www.gwtrading.com/hga.shtml
They are pretty cool, I have a MAS Supernova I picked up off ebay for a decent price. Neo Geo MVS works with it, so I can collect MVS carts with an MVS pcb, and a I have about a 6 or 7 other jamma boards, makes for some great fun! I play them more than most of my systems actually,