So are you hoping to keep the RSP-1066 for HT, and add a 2-channel preamp? Or are you abandoning multi-channel and going dedicated 2-channel? I also have the RSP-1066, and while I feel that it is a top unit in its price range, I have been hit by the upgrade bug pretty hard, and I am looking to either add a high end 2-channel pre or (more likely) get a top pre/pro with respectable 2-channel performance (like Krell HTS 7.1 or Theta CasablancaIII).
If you are doing the 2-channel route, but still want to use your Rotel for HT, make sure that whatever preamp you pick up has a "processor" or "HT" pass-through. I know that all newer Audio Research preamps have this, and I would think that a used Audio Research preamp with this option would be a tremendous upgrade for you. Bot the Cary and the CJ are going to sound pretty nice, too, but I don't know about the pass through. If you were going to try and upgrade to another pre/pro, if you sold your RSP-1066, and added your $1,000, you could problably pick up a Theta Casa Nova, which are sonically very excellent, but going for a song because they are only 5.1 channel (and have no muliti-channel input).
Good luck, Tom.