well i will oc my i5-4690k like you (maybe less than you, about 4gHz) and my case can't fit 240mm radiator, too. so i have been searching a lot these days and i have decided that for my budget (60-70euros) in my country the best choices for AIO are the thermaltake 3.0 performer, corsair h60 and coolermaster seidon 120v. so i would suggest these coolers to you too. have in mind that i specifically want AIO and not air cooling so i haven't done any search on good air coolers for this budget. some say that you can find better cooling solutions with this budget if you decide to go air cooling. i made some posts in forums about these 3 coolers i told you and it seems that the seidon 120v has the best price/performance ratio from these 3 choices but the h60 has the best quality (and in my opinion the best lookings).