I think they should trade Quis for more a veteran presence. I think the bench kinda self destructed game 3 and 5. If they can get a guy like Speedy Claxton, who's won a championship and has hit big shots in the Finals, I think they're golden. Speedy can run an offense coming off the bench too. If not him, either Memphis' Stoudamire or BJax could make the Mavs deadly too. Ideally though, if they could get Sam Cassell to sign for the MLE and have him accept a bench role, I'd say they're well on their way too a championship...
Basically, I'm not sold on Devin Harris as a back up point gaurd..Not just yet. He seems to find trouble in running the offense. Starting him at two-gaurd with Jet could pay big dividends, especially when they have Dirk and Diop/Dampier as a back up line.
Get rid of Josh Howrd too. He probably cost the Mavs a championship and for that alone, he should be traded. Trade him for Caron Butler, who does almost everything Howard does, but with better offense, and slightly worse defense.
That's what I'd try to do.
Let VanHorn go too. He sucks. Sign and trade him for Mark Madsen. He's a good character guy to have.