I liquid cooled my AW as my first project as well. I went with a Koolance Exos-2. The pump in it just died, 8 months into use. The good news is that since it is still under the, somewhat anemic 1 year, warranty Koolance will repair it. The bad news is that since the Exos-2 is an integrated pump, radiator, and reservoir my system is down until that repair is done. I’ve already jumped through the RMA hoop but now waiting on them to fix it.
I can’t say I would recommend going the Koolance route again. Go with a component system and if one mechanical part fails you can just swap that out at a lot lower cost and hassle. In fact if this repair process takes much longer I am going to pull the trigger on:
http://xoxide.com/thermaltake-bigwater-745.html
and at least I will have a relatively inexpensive back up system in case the Exos fails again.