if you are going to do some track days and stuff then the water inj can be plumbed in for safety on hot days. - it uses one on the pins in the back of the ecu to trigger a relay

you can use the existing pump(s) or go for a WRC style pump about 130 quid ish

if you have an rs500 cooler slap it on - you should be fine m8

might be an idea to get an ACT gauge or a secs monitor to see exactly what temps you are getting

Hope this helps

Mike.