i got mine from smashtv mainly due to the extras i wanted and the silkscreened boards all excellent quality and service.
there are guys who have built mb64’s in the uk, best thing to do is take a good read through the forums and also if you look in the ucapps gallery section you will find some built by uk users and if you click the links they goto the relevent sections in these forums and you can read up on them in there also.
the best thing to do at the moment is to read up as much as you can before you start. all the info you need is in the forums and the ucapps website