Congrats on your buy
I considered an RX-7 for a while but money made me decide agianst it. Now the general consensus is that the stock rad is not very good and should be replaced. Now you could buy a nice fluidine and not have to replace it agian if you plan on slapping on alot of power, or if you just want a little more and good reliability, then go something a little cheaper. Also the stock AST tends to crack and leak so it can be removed completely. The precat tends to break down and clog (very bad, leading to skyrocketing temp and power drops) and should be replaced with a downpipe. I'm not sure on the price of 7 parts in canada, but for a few thousand you can have a rock solid 7.
BTW, is it an FD or FC?
*Edit*
Also, have you bought a cheap boost gauge? If not I would recommend doing so and checking to make sure your running 10-8-10psi boost pattern. You should get 10psi untill about 4500RPM, then it should drop to 8 and build back up to 10 by redline. Also, look for a "stumble" at 3,000 RPM under light acceleration. If the car does stumble you need to realize it may be impossible to fix this problem. There are some current owners that cannot eliminate that 3,000 RPM hesitation but many others have solved the problem by improving the engine to frame and battery to frame grounds.