Hmm... maybe I'm going about it wrong, but I don't see any appropriate stand-alone ribbon controllers that aren't DIY. On the other hand, I did find a lot of awesome other controllers:
JamBass,
BodySynth,
midiGun 1.0.
Let me rephrase that, I can't find a stand alone midi ribbon controller under 28" long and at least $300. The only manufacturers I can find are Kurtzweil and Doepfer. Sorry, epic fail.