That is a pretty hard question. I suspect you'll need a lot of reply posts and some time to think about it.

The only thing I can add at this point is that generally you should spare little expense in your everyday strop and you should go cheap, cheap, cheap, on any strop you plan to put paste on.

I typically wouldn't recommend an hanging strop for a paste.

I use a very expensive strop for daily use and I used to use pastes on a piece of balsa wood (to give you an idea of how unimportant the character of the leather needs to be for a paste).