FWIW- We have a nice kit (not on website at this time) that we use on the track cars and on some of the street cars.
Ours is a true swirl tank like you'll find on many racecars. It swirls the entire cooling mass to help "clean" the air bubbles from the cooling mass for better heat disipation in both the radiator and engine. You'll see a schrader valve on the tank for adding pressure so that you can run an "air spring" for higher block pressure. More block pressure means smaller air pockets in the head, smaller steam barrier around the cylinders, and a higher boiling point (for every 1psi pressure, you increase boiling temp by ~2.5-3 degrees F. We run the system at ~30psi).
The point about pressure is quite important, as more pressure allows for much better heat dispation from the cylinders. That doesn't mean you'll run lower water temps. It means that you'll extract more heat from the block... NASCARs for instance, in some races, will run 70-100+ psi in the system, with only 17sqin of air opening to the rad, and run 300+F degree water temps. Simply put, they can do this, in part, due to the higher block pressures making the cooling mass extract sufficient heat from the block despite higher (than "normal") water temps.
The cost for the kit is ~$450. It comes with the needed hoses, bracket, and fittings for installation. It will allow use of the OE circ pump and actually cleans up the plumbing a bit in that area of the engine bay.
-Phil