Which Delhpi?

I'm writing a delphi program that will access a database(paradox, bde
etc) over a lan, (the server is nt and the client computers are win3.1)
The question is, which version of delphi do I need to buy to build this.
As a student I can't aford too much.

I have tried the borland website but it wasn't much help.

James Dustin