SQL server so far would be the best database to make use of. However, for a small bussiness the cost might not be worth it. If you have a small connection try using the MSDatabase Engine. It is exactly like SQL except that you are limited to 1gig per database. It also is alot cheaper... its free! It is Microsoft's database solution for visual basic. Although, I also like using Visual FoxPro as my back-end... and it does the job to. MSDE has good security features which is easy to use and manage.

FYI