Source the parts from local junk yards if you want to save a good amount of cash.
If you're not confident with doing some of the work yourself, then my suggestion would be to sell your car and look for a 5-speed. It'll give you an opportunity to pick something up with a few features you originally wanted and even a different color.
Goodluck with whatever you do!
Edit: To answer your question, honestly you can find one anywhere. Local junk yards, craigslist, ebay, local automotive/transmission shops. This is seriously a no-brainer...