brake conversion on ebay

Suit yourself. I bought my 13" front brake kit from Dr. Diff for less than that.

Not to mention, you can get the entire kit from Dr. Diff for about $505 with the ball joint adaptors, and just have the rotors redrilled to 5x4" at your local machinist. I bet he'll charge a lot less than $490.

As far as your rims go, you might not be able to use them anyway, depending on your wheel size, backspace, and tires. The 73+ kit widens the front track width enough to cause problems if you're wheel/tire combo is already close to your fenders.