OK, I completed my research on the 336 wheels. Thought it might be useful to post that info for any others considering this later.

The part #s are:
Front: 36116788010 for X5 and X6
Rear: 36116788011 for X5
Rear: 36116796152 for X6

If one wants to put the X6 rear (72.5mm hub bore) on an X5 (74mm), this hub adapter will work

TPMS info:
Before 10/2010, you need "Wheel electronics module RDC 433MHz" part 36236781847. An alternative part is 36236779490. (So I need to buy 4 of those).
10/2010 and later have part is 36106790054.
New valves may be needed too.