Well what they were talking about Amps for your speakers Drew, was that if your cabinet has speakers in it already, you can power them by ripping apart a really cheap pair of speakers then using the amplifier out of that cheap set (should be a stereo set of speakers), because the amplifier of a cheap set of speakers can make a good set of speakers sound just as good as if you put an expensive amp in there.
If you don't want to spend a lot of money on the speakers but want better than computer speaker quality, here's my suggestion:
go to Happs website and find their speaker section. Pick out a set of speakers that has a good frequency range that will get most arcade sounds, get em, then buy the cheapest pair of stereo computer speakers you can find. Open up the computer speakers, cut the wires to the two cheap speakers, rewire them to the two happs speakers, put the amp somewhere (which contains the volume control and what not) easy to access, and presto, good sounding arcade speakers for not that much money.
If you just want to have a volume control, almost every computer speaker I've seen has one on it, like on the front of it, so I woulnd't worry about accessing the volume control. If you have a set of speakers that have a sub with the volume control, it's possible to take out the amp, place it somewhere that is convenient for volume changing, and just extending the wires to the different speakers.
If all this information just flew by your head, cause I definitely admit it's WAYY confusing when it's just in words, then look around some projects that have this amp hack. http://www.russprince.com/cabinet/speakers.html it's not mine, but it's what I used for the basis of my own personal hack.
I kind of put a twist on the speakers hack, because I left the two cheap satellites and the 3" subwoofer on the cabinet, and re-wired the speakers, so that the speakers that came stock in my cabinet I got were all hooked up to the amplifier. The subwoofer makes the cabinet resonate, so the bass sounds great, the cheap satellites get Excellent Mid-range frequencies, but not good at all high range, and the stock arcade speakers from the early 90s get really really good high range frequencies. The complete deal sounds awesome.
http://www.geocities.com/cthulhuluke/-good luck
-CthulhuLuke