FL10 or the Prem Polish Firefly?

Im torn between getting the M4A1 FL10 or the Polish Firefly (not even gonna attempt to spell it) in the british tech tree. I have pretty much grinded Rank 3 and 4 for the French tree and the FL10 seems good fun. But I also wanna get the Polish Firefly to start off the British TT. What do you guys think?