Jrock,
I tried running a jvc rx 10 on the lows and Pany 45 on the highs and it would be a nightmare to bi amp accurately this way at any given volume level.
I currently have two modified Pany 45's in a bi amped 2-6.1 channel set up and will not be looking to audition any H/T audio gear for some time to come.
The Panys can be bi amped as they have a digital out for daisy chaining them, and to say that they better my prior 8k pre/pro amp set up for H/T would be an understatement

.
I just today gave my rx -10 away to an Employee as a Chritmas gift but it did sound better at analog than the 45.
The 50 is supposed to be somewhat better at analog than the 25/45 are so you could go that way...or check and see if the rx-10 has a digital out as it would be much better using the same model and one remote to bi amp for digital than to try and mix and match.
I beleive the rx-10 does have a digital out though and sounds pretty good for H/T digital.
But two of either would be even better ...even in stock form for H/T...just as long as your speakers are bi ampable.
Good luck
Greg