You need two things:
A union directory, and a phone.
Go pull out the CDs that you own that have the sound you're looking for, find the names of the people who played on them, go to the directory, look them up, and call them. Really. You'd be amazed at who you can get to show up, if they have a gap in their schedule. We're talking centerfolds here, top players.
Like everything in the industry, people run in networks with other people of similar ability. If you dig through the directory and find that killer guitarist you want to hire, ask him to recommend other players for the other gaps in your lineup. Chances are, you'll be very pleasantly surprised.
It's perfectly reasonable to ask for a credits list for players you don't know, and do your own research. Go to iTunes, listen to what they've done. If they don't have credits that are readily available, ask for mp3s in the style you're tracking. Nobody gets offended by asking for examples of their work (I mean, don't ask Vinnie for a demo CD, but you know what I mean).
As for how much you should pay them, there are no shortcuts. You get what you pay for. If you want players with chops and experience, expect to pay union scale, at least. You can see the rates
here. You can also see the scales listed their for limited pressing and demo recordings, which might be more in line with what you're doing.
If you want direct referals, feel free to PM. I can point you toward some A list players.