I live next to France (so have the non-military rounds issue) and the battery I am building up will be a 7x64 and a 9.3x62.
Note, if you want to get a .338 of any form, you won't be able to use it on MOD ranges.Rubbish, correct your facts
My advice would be to try and get something to compliment what you already have.
In my case the 7x64 is fast and flat whilst the 9.3x62 is a big thumper.
9.3x64: Is quite a powerful round and is real competition for a .375 H&H but even over here on the continent is rather specialist. (The 9.3x62 isn't quite so powerful but works very well and even the US manufacturers are starting to produce ammo for it which will help with the cost).
Above all, have fun choosing.
ATB,
Scrumbag