1. Pocket PC's with PCMCIA slots are vanishing from the landscape. You should make a (short) list of the models that you can buy with said slot, then you can ask Sierra if those models work with their card.

2. Antennas such as you write about may or may not work. No one will tell you (except the person selling it) that it will make any difference.

3. Once you get the PocketPC, then you look for a keyboard...