A direct pitch on top would work great. I've done it twice and one was my RIS (1.105), the other being a big Tripel. I've also done the wash thing for brews below 1.070.
I would try and rack off as much of the Irish red as possible, but I doubt you would get much flavor transfer to a big stout like you're planning.
Primary #1: Umlaut my Kölsch IV #2: Empty
Secondary #1: Belgian Golden Strong #2: Dark Belgian Strong #3: Barolo Wine #4: Framboise Lambic
Kegged: RedHook ESB clone, Fat Tire Amber
Bottles: Surly Furious clone, Kicked by a Moose Scotch Ale, Apfelwein, Russian Imperial Stout, Trappist Dubbel, Carmelite Tripel, Pinot Noir, Rhubarb Wine
On Deck: Altbier II