Can anyone recommend a GREAT converter?

I think I read some where that US air force/military bases here are like 'little bits of the USA' which geographically just happen to be on UK land. There, everything is as if it was in the USA, so things 'from there in the USA' work 'here in the borrowed UK land'  - so would of course include electricals etc.

I understand that some of the North Sea oil rigs are also wired to American standards and - naturally enough - are self-contained with their own 60Hz generators. 

It explained why several years ago my local "junk" shop had a huge box full of NEMA electrical fittings, some heavy-duty 3-phase, which one of the workers had off-loaded with some other stuff.    The shop owner had no idea what use they would be or who might want them, but said he was loathed to just throw them out, which worked to my advantage since I managed to acquire what must have been about $300 worth of brand new connectors and other fittings for £5.