Recommended coolant type

I'd look into something like Redline's Water Wetter for water with slightly better cooling properties and corrosion inhibitor. Definately need a corrosion inhibitor.
I would not use any of Evans products in your case because if you need more you will have to order it.
See what racers (road, drag, sprint) use in your area. That way you know its available.

Also reconfigure the catch can so it sucks the coolant back into the radiator as the engine cools down.
Basically you need three things:
1. A recovery type radiator cap,
2. Hose from the radiator filler neck to the bottom of the recovery tank.
3. Open hose connection at the top of the recovery tank for venting and emergency overflow.