z87 vs h87

z87 is what you want for overclocking. the h87 boards are not meant for overclockings and only let you modify the turbo boost. some asus h87 boards can change the cpu ratio as well but again, do not have full overclocking support.

you might also want to think about going z97 instead of h87. the new boards support the older z87 cpu chips and have more options. the asus z97 series are good, just pick the model which has what you want.