Sounds like you are on the right path, really looks like a tasty recipe! Great baseline to start with and you can always crank it up if you want in the future. That recipe should get you a nice IS And since it's only a few gallons you don't have to invest an arm and a leg into a test recipe.
I live special B so I would probably throw some of that in there... Maybe some chocolate malt too. But I like the simplicity of your recipe too. Imperial stouts can get pretty crazy grain bills going and yours looks good, as for yeast that is another personal preference, I usually just go with the standard American ale and I have heard the grain and hops in the imperial stouts will overpower any flavor the yeast may impart, just my two cents be sure to report back with how it goes!