Mick,
I suggest Bastogne and Bayeux museums.
As far as I can remember there are a good amount of uniforms.
Could be useful have a look at their sites on the net.
Marco
I understand the National Army Museum in Chelsea has just re-opened after a renovation.
I've no idea what it's like though...
Being from Belgium I can only recommend Brussels (incredible collection and very nicely displayed although the story behind this setup is rather depressing) and of course Baugnez 44 & the La Gleize museum (which are of the same collector iirc). Especially Brussels has a lot of display cabinets with lots of uniforms but nothing beats the atmosphere of the Baugnez 44 museum which itself also has a lot of nice displays...