Best version will be the latest version.
The B is an older model, non LED screen and slower than the later versions with their more powerful processors. On the plus side though, the B's are now cheap and have been sold on here for £350-£400 max.
The latest version is an H version and one also has DAB as well, Eddie-NL can supply these, although its twice the price of the above price.
Have a look through this...
http://www.mk5golfgti.co.uk/forum/index.php/topic,50983.0.html