Dont think you can SVA a 5 at present, there isnt a model report avaliable for it.....
When i started looking, i wanted a 5 but the import company promptly told me its a no-no.
Only way to get it registered is to get a model report done yourself.... which should be a good couple of G's or so. Seems to be a fair few recently imported 5's around at the moment, people just havent realised the rule change means you cant register them. Im sure someone on here can give more specific details, but thats the situation as i understand it.
So, all in all, find a uk 5 or go for an imported 6.