Giving the FI as youre curriculum vitae is not very helpful for us to suggest what to learn next (as I'm sure you've seen ad nauseum on other threads). If you have large hands, go for the 10/1, as I found it rather easy because of this reason, while the 10/5 has given me enough trouble with fingering to stave me off for a while. But why limit yourself to these two? I much more respect the leser known ones (and tastes of people who choose to play them instead) such as 25/7, 25/5, and 10/7.