Besides the ranges mentioned, Brigade Games will launch a FiW Kickstarter tomorrow.
https://www.kickstarter.com/projects/brigadegames/this-very-ground-french-and-indian-wars-28mm-miniatures?ref=profile_saved_projects_liveModels are sculpted by Paul Hicks, which means they will be roughly the size a Perry Miniatures and North Star Figures, i.e. slightly larger than Conquest/Warlord but smaller than Galloping Major.
Eureka Miniatures also has a few models for FiW. The Highlanders are true 25s, which means they are quite small when compared with other ranges, even Conquest/Warlord. However, the Virginia Regiment Provincials are normal 28s. They fit well with Perry, Brigade and Conquest. Problem with Eureka is that except for Aussies the shipping costs are crippling.
I have British and Provincials from Galloping Major, but probably I will sell them because all my Indians and French are Conquest and GM tower over them. It is exaggerated, even at a distance. It's a shame, because I like GM and I have 12 Hatmen and one officer painted, plus quite a few unpainted. However, I want some consistency and with 60 French and Indians painted, plus 24 Eureka Provincials, I prefer to rebuild the British which I only have 12 painted.