Clearly they want cap relief which means they don't want a 2013 1st and the team must have cap room. They also want to trade Robinson to go after Dwight. All of that means, they probably don't trade Robinson until after free agency starts and then only if it appears that Dwight is truly interested. Thus, they need a team with cap room and that would be willing to give up a pick in 2014. Cleveland seems to jump to that top of that list since they have their own pick and Miami's in 2014 (they also have Memphis and Orlando's 2nds in 2014) and Robinson would seemingly fit in well with what the Cavs are doing (add him to Noel, Zeller, and Thompson and you have your big rotation for a decade).
Robinson to Cavs for 2014 1st (Cavs pick lottery protected or Miami's if Cavs in lottery) and the best 2nd rounder the Cavs have (theirs, Orlando's or Memphis'). That would seemingly fit with what Houston is doing and seemingly what it wants and would be a solid trade for Cleveland.