Which SBF cylinder heads?

RPMs can be had with the 1.90 intake that can be used with the stock slugs if you want.

RPMs can be had for around the $1100 range. They also have a 60cc chamber and will work with your headers without any mods. They are also a good match for your intake.

http://store.summitracing.com/default.asp?target=/egnsearch.asp&N=400065

I have never seen RPMs anything close to $1800.

Definately one thing to consider between TFS and non TFS heads are with the TFS, you can have 2.02/1.6 valves while you have to stay with the smaller valves on the other heads to work with your stock pistons. The TFS heads are definately better flowing than the AFR 165's. If you're comparing to the 185's it's close to even (TFS has more low lift flow, max lift flow isn't everything) but I believe they come with the larger valves you can't fit. TFS heads are also fairly cheap for aluminum heads. Summit has them for $1150. They should have the best price since they own Trick Flow. They come normally with 170cc intake runners but can be opened up to 205cc or possibly more without a problem for future growth. You can even buy CNC ported 205cc intake TFS heads from Summit for about the same price as the same size AFR's and the TFS ones will outflow.
-Brian