Yes I could go out and by a Pioneer BDR-S11J-X/BDR-S11J-BK/BDR-XD06J-UHD but I need a slot loading 4K blurray drive. (as the Pioneer one won't go inside a HTPC as its top loading!)
Reading: http://forum.blu-ray.com/showpost.php?p=13271422&postcount=108 it says there is:
Logitec LBD-PUD6U3L (external)
Logitec LBD-PVA6UCVBK (external)
Buffalo BRUHD-PU3-BK (external)
LG BU40N (laptop)
LG BU50N (laptop)
But finding the first 3 outside Japan seems impossible and the last 2 I've read they don't support the correct AACS 2.0 etc
SO.. What slimline 4K blurray drives are available and work? I'll buy one today if someone can identify something which is actually available?