Looking for a mobile solution

I am looking for a mobile solution to meet the following needs:

1) Support a database with 1500 ? 2000 records. (Access /Visual Basic Database).
2) Quickly view these records while in emergency or crisis situations.
3) Enter Data and make changes to fields while working out in the community.
4) Ease of use for viewing and data entry.
5) Network connection.
6) Not immediately, but at least upgradeable for Internet and email connection. (dialup or wireless).

The solution I am looking for will be used by a nonprofit agency. Meanwhile I know my options range from Palm OS devices, Windows CE devices, and laptops.