Vintage Synth Repair

Hey everyone, I'm a newbie when it comes to electric pianos.  I've 
played piano for about 4 years and I also like composing techno music 
on the computer with Acid (by Sonic Foundry).  I want to get an 
electric piano (sub $300) that will let me connect to my computer and 
create my own unique pieces from scratch.  Hopefully a piano that 
lets me create my own loops and assign to certain keys or something.  
Anyone have any ideas on a good keyboard, software, or anythin else I 
might need to design my own music?