Hi, The xx4 dogbones etc are the same fit as the xxx4 cvd's both front and back as hubs, and carriers are all the same, this also is true for the X5 parts, you could try DMS-Racing in watford, he might have some CVD's or MIP's for the X5.
Might be a bit tight on mail order now but if it's not urgent speak to them.
http://www.dms-racing.com/