RIS recipe in progress

I'm working on a recipe for a Russian Imperial Stout. I plan to oak age this brew. Now, I've come across a lot of discrepancy in mash temp for the RIS. Don't mash to high for gravities sake, but you also want some of that lovely mouthfeel. I've got a range in mind for this brew, but I'm curious to if any of you have made this style and what worked best.

So before I post my recipe for eval, I'm curious to what you all think a good mash temp is for a heavy RIS recipe. Please post experiences too.

I really appreciate the input!