You will need valve springs that are compatable with the valve lift and make sure that there is enough clearance between the valve retainer and the seal/guide surface. 5.05 lift shoudl be fine but in never hurts to check. with KB pistons there will be no problem with 505 either. They have some pretty deep valve reliefs.
Depending of course on how much your are going to mill the heads the lifters preload should not be a problem as long as you don't bottom out the lifter cup. Hyd. lifters have a lot of forgiveness built in. Again unless you are foing to mill a h of a lot shims will not be needed. They are not made to correct/make up for pushrod length.