I'm not a pro clocker to be honest, my efforts have been successful due to luck and good cooling so I'd check the overclocking guides around for that but I can help with the chiller and if you aren't getting started until september then now is the time to start researching and learning all about the pros and cons involved,
You may find simply increasing radiator space achieves the result you want
As a starter exercise, find out your dewpoint and this will let you know a rough number to aim for maximum cooling with no condensation problems
Make no mistake, you are in cooling school now and the end of term test is firing up your rig with the new loop, I needn't mention that failure will be infuriating and potentially fatally expensive
Moto