Just get the best u can afford mate! If you can get a H version off eddie for £600ish I'd snap it up
(sorry ed I don't know how much u sell em for)
Mine is a B version upgraded to a F and I have the latest V8 maps.
As its been upgraded above a B the SD card slot now accepts up to a 32GB SDHC card on which I store all my music on now. The B version only supported up to a 2GB SD card.
Other features have been added and upgraded with the update too!
The new H version will have all the latest updates plus newer features and maybe upgraded parts.
I love my RNS to bits, but the Only thing that lets it down is the screen.
The newer LED screens are miles better and alot brighter.
On an overcast day my screen is nice but dim.
I'd recommend a C version or above, but also, given the choice, if I was buying one again, I buy one from one of the forum sellers like Eddie or Darren.
You will always get more help and support from these guys than you would from someone in Poland, and they are clever guys too