I know full foot fins are less forginving size wise, so I am trying to estimate size the best I can since I am probably buying from scubatoys. I know all the benefits of open heel, so i don't want to go through that, but for many reasons I want a pair of full foot fins, and I have a narrow foot. I normally wear an 8 or 8.5 in womens, so I'm guessing that I would need a 6.5 or 7 in a unisex fin. Should I go smaller since my foot is narrow? And also, anyone have any suggestions for a good, affordable, model? I've looked at the volo race, avanti excel, and several cressi models as well as a couple of aqualungs?