AV receiver for 4 ohm speakers?

I'm ready to upgrade my AV receiver to handle 6.1 channel sound, but I'm concerned about some posts I've read complaining that many of the "mid-level" 6.1 receivers don't handle 4 ohm speakers very well (the Onkyo TX797 comes immediately to mind). I'm using NHT 2.3As in the front, which are 4 ohm. The rest of my speakers are all 8 ohm (1.3As and SuperZeros). Anyone out there have any suggestions? I'd thought that maybe something like a Marantz SR8200 would work well . . . I'd like something that I can get new for under $2K.