you prob will have problems with fit.
I have those bindings in the L/XL and i wear 10.5 burton freestyle boots from 2007 and they fit well in the bindings. it is usually good advice to go with the larger size when on the border of binding sizes. since you don't have the larger size to choose from i say you should look for another binding.
i have the bindings and they are nothing special, but they do their job. look for other bindings, Flux, Rome 390s, or union Forces, there are plenty of alternatives.