www.amazon.com. If you prefer brick and mortar, you can go to Fry's or Radio Shack, if you can find one that's still open.
A couple of popular models around here are the Uniden Pro520XL (about $50 and fits right in the center console) or the Cobra 75 WXST (about $90 and has the controls and speaker built into the handheld microphone, with one very small hide-away module for the antenna and power connections). There are a million options when it comes to antennas and mounts, and just as many opinions about which is the best to run with. Most folks in the group run a 36" or 48" fiberglass whip antenna, but some are running a metal whip which handles tree branches better.
As far as mounts, again, a million options that range in price from $15 up to about $80 and have varying degrees of difficulty to install and use. Everything from a magnet mount with a piece of coax running in the back door, all the way up to 3-axis adjustable hatch or hood mounts. You'll find plenty of options if you browse around in the SCCX Comms section of the forum. If you don't find the info you need over there, just post up a new thread and you'll get tons of answers.
