New to the two channel world - Advice needed on preamp


I am new to the two channel arena, but have been in AV my entire career. I am looking to find a solid preamp to match with my system.   I would be open to integrated amps if they are a better option.

Current Rig

Paradigm Prestige 85F’s and Prestige 1000SW Sub (Not sure if I really need a sub or not, but I have it nonetheless)
Bryston 4B-ST
Sony ZA3100ES (I know its an AVR, but it had the requisite preouts)

I listen mostly to FLAC files off of a PC. Looking to stay under $2K. Any advice for a newbie?
theaudioninja
Are you using the sony for your digital conversion as well? If so, does your stated budget need to cover both your dac and preamp needs? Are you using the sony for bass management or is that handled at the sub?
Ghasley- yes, right now the Sony is working as my preamp and dac. I can manage the sub from the front panel. 

Would a device like a Cambridge 851N or a NAD C658 work for me?  They seem to be a preamp, dac, and network streamer wrapped in one. 
Lots of things will work but what is it you are trying to accomplish? Separates or integrated 1 box system?
"...but my experience with Bryston is they do really well with a tube rather than SS front end. "

I fully concur.