I would go with a jrok encoder. I found them to just be better in general. Unless something has changed, the Neobitz still relies on the AD724 which is not that great a chip. In fact, the only time I have even seen the chip used in a professional setting as it were, was on Trident VGA cards that had s-video out. If you end up buying one you will end up probably having to buy a sync cleaner from the Jrok guy anyway, because there are a lot of arcade boards out there that have sync issues with the AD724 and AD725. I have found games like Time Killers, Primal Rage, TMNT, Boogie Wings and others have issues with it.
Power supply wise, you can either go with an arcade psu, along with what that entails, or you can go with a older AT, older ATX, or newer ATX one. Newer ATX ones however will not supply -5 volts, which some boards need to run correctly, so depending on your needs you may be doing some voltage converting. If you went with a older AT or ATX, make sure the -5 is at least able to put out .5 amps if possible (more is better), and make sure to get a good quality, reliable brand psu. If used, recap it using good caps. Case wise, you can get a large pactec case to house the parts. You will need a dremel and drill kit to cut and drill holes, and a file to file things down. If you want to maintain DB15 joystick port ability, you will need to order a couple of db15 midi/gameport jacks to use.
http://www.ebay.com/itm/Lot-of-2-DB15-Male-solder-cups-and-metalized-plastic-hoods-17010-17208-/160965854861?pt=LH_DefaultDomain_0&hash=item257a50068dAs far as the other parts go, contact the makers of the encoders directly I guess, and you can check ebay for power supplies, power switches, pactec cases, jamma harness, etc.
