I tend to prefer my stouts to be English in interpretation, and 9-10% is about the ABV wall for a lot of English yeasts. I love Wyeast 1469 West Yorkshire Ale for almost anything English, but you may have to prime with champagne yeast.
If you're going more American styled, there's quite a few yeasts that'll get the job done.
Alternatively, I think Wyeast 1728 Scottish Ale would be a good bet. Versatile with some nice esters if you want to go warmer, but not "English" per se, alternatively very clean if you want to ferment cold. Plus it's a workhorse that'll easily tolerate 9-10% ABV.