Stay away from the Lexicon processors if you value high end, clear, musical, refined sound quality...my experiences anyway. The Classe SSP25 used should be all you need, or the Krell HTS that's on the used listing here pressently for $1800 will be PERFECT for you for refined, ultra clean(as it gets!!!!) for HT 5.1! Look no further than these two, really. (used Class SSP25 THX pre/pro, pure dirrect w/analog through puts for all inputs is around $1k used range).
As for amps, the inexpensive(relative) used ATI amps are a near MIRROR match for the Krell 250a amp. you should find a 3 channel(or bridge a 6 ch) ATI for your purposes, no problem. Otherwise, the used Krell 3 channels are your sonic match for your existing.
Good luck...and keep the sound quality in tact!
As for amps, the inexpensive(relative) used ATI amps are a near MIRROR match for the Krell 250a amp. you should find a 3 channel(or bridge a 6 ch) ATI for your purposes, no problem. Otherwise, the used Krell 3 channels are your sonic match for your existing.
Good luck...and keep the sound quality in tact!