You might try the HTM-200 SE - they are relatively small and they are sealed so they can be wall mounted. If you call Ascend they often have B-stock so the price might fit your budget.
I only mention it because of the speakers listed...
There are several comments about some common AVR's not working well with the LS-50.
The only solutions presented so far are 2-channel amps.
Can anyone recommend a 5.1 (or 7.1) AVR solution that would work well with LS-50s in HT setup?