I would recommend CASL from CASLsoft.com.
1. It is very cheap.
2. Easy to learn.
3. Can sync database through ODBC (so VFP works).

I have done one project where the salesman can book orders for Medical whole seller on it and sync to VFP data. I used Palm Vx and CASL and it took hardly 15-20 days to learn and write the whole thing and is working good.

Rajesh