I sort of have the same issue but in a way different situation. Most people recommend to ditch lga 1155 because it is becoming obsolete fast with all the new intel processors having better upgradability paths, as well as more motherboards available for years to come. If you don't want to spend a lot right now, then you can probably pick up a 3000 series i5 or i7, whether it is K unlocked or not IMO depends on what cooler you have since usually, the performance gains of overclocking are often balanced out by the better motherboard and cooling solution required for a stable clock. You have a good board though which makes it hard to choose an older cpu and overclock or get a brand new 1151 and cpu thats more relevant.