I have one of these 6-1 boards from Jammaboards. I haven't touched it since I bought it.
http://www.jammaboards.com/store/6-in-1-multijamma-switcher-pcb/prod_250.html
I'll sell if for $80 plus shipping if you're interested, but I would HIGHLY recommend doing a search on it here for reviews and comments first as I wouldn't want you to be disappointed. From what I've gathered, it works well for simple Jamma PCB's, but anything more involved like Golden Tee's, Mortal Kombat's,etc will require some modifications.