1/9th scale is about as large as full sized figures go in miltary subjects, and there aren't a whole lot out there. Warriors puts out a lot of the larger figures. It seems to me that they just put out a 1/6th scale military figure recently, a WWII GI if I recall, that was to be the first of many, so keep your eyes peeled (I can't find which magazine I saw it in, but I'll post it if I find it). Dragon also re-issued the old Esci 1/9th scale motorcycle kits, with the figures that came with them. Busts come as big as 1/6th, but they are simply busts. Also look into figures by Kirin and Jaguar, as well as vinyl kit manufacturers like SOL. They all make great 1/12th and 1/9th scale figures. Of course if you're into fantasy/sci-fi, there are hundreds of figures in the big 1/8th and 1/6th scales to choose from.
I've been sculpting military figures almost exclusively in 1/9th scale, and now in 1/6th scale, over the last five years or so, but I haven't done any for production, so they're all one of a kind. But my decision to do so was inspired entirely by the lack of subjects in these scales. My first 1/6th figure was a Samurai archer I did last summer. I'm now working on a WWI German having a bottle of wine on X-mas day. He's also in 1/6th scale. His M1898 Mauser stands a whopping 7 1/4 inches!