Auld,
I agree, loyalist troops would be a great and necessary bolster to the game. One way to do this is to take whatever "Continental Militia" or "Patriot Guerrilla" and make it into "Loyalist Militia" or "Loyalist Guerrilla." As to regular Units, there was a British Loyalist unit called The Queens Rangers, which were the successor of Rogers Rangers within the British army. There is also the Kings Royal Regiment out of New York, and Butlers Rangers that saw action in the North all the way out to Ohio. There is also the American Legion, created and commanded by the turncoat Benedict Arnold, which was another light raiding unit. There are several more battalions of Loyalists troops, most of which would be considered "Provincial Regiments" by the Crown, they would be dressed in a similar red coat, but the rangers were usually dressed in green, and the militia in blacks, browns and grays of their own choosing. Simcoe who commanded the Queens Rangers in America actually defied an order by the the king to make all his men wear red, Simcoe said that it was stupid, and kept the men green.
Bear
ps...this might help with the legion as well... http://www.mersey.ca/tarleton.html