I wouldn't bother with a custom loop for a first build. If you're planning to overclock the CPU, an all-in-one water block would be a good investment, but if you're only going to run at stock speeds, then a decent air cooler like a Cooler Master 212 Evo will do the job perfectly well. The stock coolers that come with the CPU are barely enough to do the job, so an after-market cooler of some sort is always a good idea.