how to pick a preamp?

Due to a personal ephanney (was going to build a 4 ch. Stereo) got the 1st amp a parasound hca 1200 set it up with a B&k ref.30 for its capability of 4 ch stereo. After listening to just 2 ch stereo (as I was told, (if not scolded) for a few months I understand now!!! It can't be improved by more chs. So new direction-- going to keep it 2 ch.but now concidering a diff. Pre as I love the sound I get from the hca 1200. How do I evaluate a good pre vs a great pre. Funds are limited to about 3 to 5 hundred for a used quality vintage pre. I want accruate, quiet warm stereo sound. Any help would be appreated!thanks to all those prevouis members who tried to educate me earlyer. It was not in vane just had to here it myself and you were right!!!
Do you need a phono input or just line stage and do you want to try tubes ?
Yes I would want phono, as far as tubes go if affordable and replaceable (tubes that is) no objections but nieve as to the differances in proformance.
I used to own a Quad 99 preamp and thought it was very good for the money. It has a phono stage, tone controls, and remote.

I have an Audible Illusions 2c tube preamp that recently had ceramic tube sockets put in by Art Ferris at AI. It has kept me happy for 20 years. Occasionally you'll see one pop up on Agon for about 400-500. With a good solid state amp like you have, you'll love the sound. The tube socket upgrade made the preamp way more quiet and eliminated tube microphonics (subtle ringing). My preamp sounds significantly better than when I bought it in 1991. I've upgraded my entire system using Agon in the past 2 years with the exception of the preamp. It also has a very good phono section in it. If I were to upgrade mine, I would probably only consider 2 companies--AI and Modwright. It would take about 2000.00 used to make a noticable improvement. I just don't feel the need.
Thanks for all the imput so far,very helpful! If I can help finetune peramators, would need a direct mode as I prefer direct over stero mode, I'm lazy and would like remote control phono, tape inputs also I intend to play with a dbx unit I have for the tape and phone and fm modes,an inboard tuner isn't critical I've been streeming most of my source material.( Set up my comp. As a media player and I can bluetooth from internet or my phone 32 gig of alblems and. cds. But" QUIET" is isenetial the parasound is so quiet that before I got used to it I thought it was cutting out between music passages,just dead silent. Don't want to import any noise!