I think one of the big issues I need to consider re: the breakout box thingy (below) is whether my iBook has USB 2.0 ports, or 1.0 ports. I'm not too sure and it's at home, and trying to figure out from Apple's spec pages which model iBook has what proved to be an exercise in frustration.
So...I guess the suspense will continue until I get home (at which point, the suspense will still continue, but I should have one more piece of the puzzle to plug-in.)
UPDATE (4:20PM): Turns out it has USB 2.0.... still none the wiser...
UPDATE (5:31PM): Okay, I'm clearly leaning towards the UX2 right now. Found this user review, which was positive. It appears that latency is not an issue.
UPDATE (10:43PM(: No idea what I'm going to do. Think I'll sleep on it.