Didn't realize they had those back in stock. Looks like they're offering the -5 mod that xenomorp has up on his youtube. Besides not carrying -5 on the boards, it doesn't carry the test switch lead, and from what I've heard/seen, the relays on them are woefully underpowered and poorly laid out. I have one and have been meaning to do the -5/test mod on them, but also want to replace the relays and just haven't had the time to figure out what needs to go in there. The relays are lower amp rating than they need to be with some combinations of fullly loaded board, and they sometimes die, resulting in a 5-1, 4-1, etc as they die off. Now that I've dealt with a lot of other projects, may be time to put that at the top of the list. I'll post a thread in repair with relay swap details whenever I get to it, which might be a while.
*e* Yes, you could start w/ one of those (check the board manuals/schematics to see if you need -5, you can probably do that mod yourself for a hell of a lot cheaper than the 20 bucks, someone link xenomorp's youtube of that) and use it to switch between the two, depending on how the guns are done you might be able to put the leads together (possibly requiring diodes, again, xenomorp's multi kombat has details), you might be able to install some sort of switch, or you may just need to swap the connectors back and forth. There are other multi options out there, the cheap ones are generally total crap, search the forums for multi jamma for threads that have been around about the various switcher options.