If your market is small enterprises, do not use oracle. Their licencing is way too expensive. Small enterprises do not have the need for the power of oracle, nor do they have the esire to spend any money on a product that will cause problems for them. By problems I mean, they do not have the cash flow to keep a full time DBA who will charge around $50.00/hour to maintain a system that used to run well on an Excel spreadsheet.
Oracle is for databases with terabites of data. Use SQL Server or MSDE (msde is free). Really, Access may suffice for smaller business if used properly.