As much as it may tick some people off ...
If price is no object and you are looking for the ultimate solution, then I would wait until we see what UltraCade's gun I/O board is like ... no little plasticy hair dryer (original version) / water pistol (new version) is going to compare to a set of real arcade guns (y'all can have my Happ guns when you pry them from my hot, sweaty hands!).
Now it could be that the board and driver will completely blow, but then again, it might be worth waiting for.
Cheers.