What speakers would match RTi28s as rear surrounds?

My system currently consists of a CSi40 center; RTi28 mains, surrounds and rear surround (6.1); and a SVS 20-39CS+ subwoofer rig. When I bought the speakers, I only had a 6.1 receiver, so I sold the other 28 I had to another Polkie here who needed it for a 6.1 setup.

I recently bought the Onkyo 705 (which rocks!) to replace my old receiver, and want to step up to 7.1. I'm looking for either another pair of 28s (or even a single if someone had one) or preferably a pair of 38s to swap out with my mains, but if I can't find either... any suggestions on what would match up nicely to use as rear surrounds? I'm going to have to do some interesting down-angled mounting (probably with ceiling Omnimounts) because of how close the couch sits to the back wall, but I'd like to match up to the sound of the RTi28s as much as possible so there's a smooth transition across the rear soundstage.

Thanks in advance for any suggestions.