I used a Fobus paddle for a short while. Never again. I'll stick to belt loops from now on.
If you are planning to carry open, then perhaps a snap would suit you best. I have seen open tops while carrying open.
If you are to carry concealed, I would stick with the open topped. Since nobody will be seeing your concealed handgun, the extra retention would probably not be neccessary. Also, if you are to draw your pistol while concealed, you would want as few obsticles in the way as possible. You'll already be pulling a shirt and/or jacket out of the way as it is.
I always recommend Galco or Milt Sparks for leather holsters. (They are the only ones I have experience with.) They are top of the line holsters and have many different styles that will suit your needs. You will soon find that one holster will probably not be enough. Different holsters for different applications/enviorments.