I've owned or used a number of comps over the years. I remember reading an article titled "Chicken or Phish". It basicly seperated compressers into two camps, the chicken pickin' Dyna comp or the fat sustain Phish band Ross style compressor. Decide where you want to be that will narow your search.
Ross style Keeley 2 knob, Tone Press, Compressor Retro, ect.... Dyna Comp, well, Dyna Comp I guess. Good Luck