Montrose Doublet

[MacMillan of Rathdown]

I think you'll find a Montrose way too warm for wearing in this neck of the woods, especially if you go for a double breasted jacket. Sheriffmuir's are another option, and while not quite as warm as a Montrose, they are still pretty warm for this part of the world-- they are also the hands down most expensive jacket you can buy. I have, however, seen one made from a USMC officer's mess jacket-- it looked spectacular.

If you are looking for something more stylish than a PC, you might want to consider what used to be called a "Standard Doublet". These work well with both white and black tie, and because they have an open front, aren't nearly as hot as a Montrose.

Virrtually any supplier worth his salt should be able to supply a doublet-- there are a lot of recommendations coming your way-- check them out.