Thanks for the warning, loren85022.
Regarding the cell amplifiers: Wilson makes several cell amplifiers, some higher power, some lower power, some intended for the phone to be nearby, and some intended to cover an entire building. I haven't found a convenient chart summarizing the choices. Anyway, I picked up a Wilson 801201, which looks like a high gain unit for phones in cradles. It's still in the box, and I'll report back on how it works in a few months.
Regarding antennas: Thanks, GMAs, for describing the options. Alan Applegate at
http://www.k0bg.com/ has great information. I spoke with him briefly, and he was very helpful -- in short, there are a lot of choices for mounting antennas, a lot of compromises, and no universal answers. For me, I have a fiberglass high-top, so mag-mounts and permanent mounts (mostly due to height) on top are difficult. I'm going to try a VHF/UHF antenna mounted on the driver's side hood seam with a Pro.Fit UNANTPF NMO antenna mount and a PCTMDL-RCVR GPS/WiFi/GSM antenna on the roof. If the hood mount doesn't work well, it won't be too much trouble to move the mount forward to the bumper. I still don't have a solution for HF, and I've pulled extra cable to the front and rear of the van so I don't have to tear anything up when I do find a solution. I'll report back on how it works (or doesn't) in a few months.