Couple of quick replies:
1. Don't overthink your forge. Search the site for the JABOD forge or the 55 forge; either will serve you well and are easy and cheap to construct.
2. For an anvil, you need (a) solid steel and (b) depth below the hammer. A truck axle, a piece of railroad track, a chunk of forklift tine -- all these make great anvils IF you stand them on end.
3. For your air supply, you don't just need CFM; you also need static pressure. Not sure if a computer fan will have enough, but I admit that I've never tried. However, a flea market hair dryer will work just fine.
A word to the wise: take some time to read over the earlier posts in the forum. You will find a lot of people have tried foolish things as they were starting out; you can save yourself a lot of grief by learning from their mistakes. (For example, I myself initially planned to make concrete-lined forge in a bucket, fired with a weed-burner from Harbor Freight. That was a bad, bad idea.)