I've had this talk before with others, the dream of getting two seconds from them for a nine spot jump without giving our second up is pure fantasy in my mind. Of course, we should ask for that and see what happens.
Just for frame of reference, the pick value chart, which isn't bible by any means but a good thing to look at for an idea, has our number 6 overall, our third, both tradeable fourths, and our tradeable sixth still worth slightly LESS than their 15, 43, 45 (forget about 33). It'd be an all-in move, which might turn out awesome with four picks in the top 45, but a move I'd highly doubt we'd make.
If you want 33 and 43, along with 15, we'd have to give our first and second, and we could probably get their fifth. That isn't enough of a change for me to make that big a move.