h22a will be easier and cost less. H22 swaps are pretty common and there is a good amount of info on them. However, k20 swaps are a lot newer and not quite as tried and tested as the h22.To get a good answer we really need to know what you are using it for... Daily driver, drag, track, etc.You might also want to consider boosting your f-series. that can yeild a good amount of power as well.