Need help deciding on water cooling set up?

SO I really want to get into water cooling, but I am not sure where to go really. I don't want to break the bank, just get a good loop that is both price efficient and performs well. I have an i5 2500k currently at 4.2GHz and I would like to set it up with it's own loop. I also have a gtx 580 that I might cool later, but it isn't a priority right now. My case is an Antec DF-85, and I am wondering if you guys can help configure me a system. Is it possible to get a good CPU loop for under $300, preferably $250 or under? Can someone give me a good, working system for a good price. I was wondering, will a 120 x 3 (360) rad work in the case?

IF you need to know any more information or anything just ask, i'll give it to you

I was looking at the Rasa Rs/x 360 and 240, and it looks good... only problem I have with it is that the performance seems just okay, and that it wouldn't stand up to upgrades over time, when i branch out to graphics cards and what not.