Don't confuse fit regarding saddle position with fit related to stem length. Sounds like you need a full, professional fitting. You will just get into trouble moving stuff around at random. If you have concerns about your fit, you need to get that squared away.

Regarding saddle choice, I recommend buying your first one from a brick and mortar store that has a trial program (as was already mentioned by someone else above). It is worth the cost. Once you know what you like, you can buy future saddles of the same type online if you like. It is worth the initial investment to get the right seat.