I am using an Onkyo 656.  I just bought a used set of Paradigm Studio reference 100 V.2 speaker's to replace my Paradigm Monitor 7's.  I have Paradigm mini monitors for surrounds and backs.  Running 2 12 subs.  I have a Paradigm CC350 center.  I probable need to upgrade the center for a closer match to the Studio.  I tried running Phantom Center but did not like it.  Any suggestions what to look for to replace center?  Depending on $$ I going to try to find used.  It does not need to be Paradigm.