I made a jukebox a while back using some altec lansing speakers, which just don't cut it for me volume/quality wise.
Volume, I think everyone can understand the universal idea when you say "they don't cut it". They don't get loud enough for you, right? "Quality" is something highly subjective. Just what exactly are you referring to? There's no way to know what you're meaning, so how do we go about helping you? Are you meaning that the size of the speakers simply don't allow you to do what you want? Do you mean they don't put forth a clear-enough sound that you're looking for? Do you mean they don't put forth enough bass for you (and do they include a sub or not - that pic doesn't tell me if a sub is specifically in there, and if it's part of the speaker setup you think isn't up to snuff, quality-wise)?
There really hasn't been enough background and explanation given before you went on to tell us what you're wanting to do future-wise, when you might be able to get along perfectly well with a BETTER set of PC speakers for far less dough than you're looking to spend, as well as far less headaches trying to figure out compatibility - the PC speakers will simply plug into your soundcard, and away you go. Easy peasy.
As others have said (and I can personally attest to), other PC speaker setups can work just fine. I've got a Logitech setup that is pretty damn good (I'd say EXCELLENT!) for an HTPC I have set up in my bedroom. In a larger room, it might be lacking quality-wise.
See what I'm saying? More info, brudda, and nice job on the juke!