@Lochekey Thank you. I already got a very nice diy glass reservoir. I have no space issues
I'll just get the 240 and then test it and just get another one if it's not sufficient.
The ideal answer would have been (which is a bit of mashup of all you answers): You should get at least something like the Corsair H100i Extreme or Thermalright True Spirit 140 Power. If you have to diy it be carefull of mixing copper with aluminium since alu corrodes the copper. (It's called Galvanic Corrosion) There is rust and algae growth in your loop this can kill your pump you should really read up on watercooling
it can be very costly if something goes wrong! Here are some links you should watch/read:
http://www.overclockers.com/beginners-guide-water-cooling/
http://forums.bit-tech.net/showthread.php?t=228676
http://www.xtremesystems.org/forums/showthread.php?269467-Watercooling-and-Algae
http://www.overclock.net/t/740318/cleaning-your-loop-after-bacterial-algae-infection-with-pictures
You should also think of using 360 rad with 3 fans since the diy system might not be as efficient as a bought set.
Something like a silver coil (kill coil) could also be something you might want to invest your money in.