OK, here goes:
Given the OG of this porter and the full bodied mash, contrasting with the somewhat subdued hopping rate, my feeling is we need something relatively attenuative. However, it can't be too dry, lest the roastiness of the brown malt and chocolate malt become too overbearing.
We're going with mild amounts of flavor/aroma hops that should meld well with the roast and toast flavors, but will be relatively minor players, so other than lingering sweetness and maltiness, the party could get a little boring. As such, I think we need a yeast that's going to bring some interesting hors d'oeuvres by way of some fruity esters. These will hopefully peek out from behind the coffee and chocolate first string, enticing you to ask, "what's back there?"
With that, I'm selecting
WLP023 Burton Ale Yeast from White Labs or
Thames Valley Ale 1275 from Wyeast. If dry yeast is your thing, I think Nottingham would be your best bet; I like Safale S-04 but it's not the ticket here, and there is a Mangrove Jack's M79 Burton Ale, but I've not used it nor read really favorable things about it.
We could go with a drier, more attenuative strain like WLP007 Dry English, but I fear this would make the beer equivalent to drinking cold day-old coffee. Not a pleasant thought, as far as I'm concerned.
Thoughts? Comments? General ridicule?