Buying phone for Replicant

[petercstevenson at telus.net]

Hello,

I am planning on getting a used phone on which I will install Replicant.
I am looking at a Galaxy S or a Nexus S, so that I will have camera
functionality. I have a few questions:

1. My understanding is that some phones won't work with Replicant, i.e.
CDMA phones, but that if a phone has a SIM card that it should be OK.
Correct?

2. Will I then only be able to use my phone with carriers that use the
GSM network?

3. There seem to be lots of variations on these phones. For example,
there are Galaxy S Vibrant or Galaxy S Fascinate phones. Do I need to
make sure that I get an "International" i9000 version, or should any
Galaxy S phone work?

Thanks,

Peter Stevenson