Cooler Master Hyper 212 Evo is probably the best and budget CPu cooler out there. However, you can't guarantee that it will cool your overclocked CPU.
I would recommend a Noctua NH-D14 or a Corsair H100i if any of these fits your budget. But if not, then the CM Hyper 212 Evo will have to do and if it overheats too much, then you may need to underclock it to 4.2GHz.