I would go with the epifani ul30s2 as well, it sounds beautiful with the tf550. I can't say enough about thunderfunk and epifani, both are amazing products and you won't be dissapointed.
Dream set up
thunderfunk 750
(2) epifani ul310s2 cabs
can't wait!!!
+1.. I always had very good luck with the TF/310UL... that mid punch of the TF evens out the rather wide and 'mid polite' voicing of the 310UL (especially the II version), and the Epi tweeter provides a touch of upper treble sparkle to the TF.... almost a perfect combination of lightweight, loud, punchy, articulate. I like it!

