So total expenses:
1. E70 X5M front calipers (used) $800
2. Front rotors F85 X5M 395mm $564 (could have saved money and went for cheaper aftermarket drilled ones, but when I found out cheaper aftermarket option already ordered oem, so it was too late and cumbersome to deal with returns, so I stayed with oem F85 rotors)
3. Stop Tech 345mm rear rotors drilled and slotted - part# CENTRIC 12734095R and 12734095L $180 (for 50i stock calipers): rockauto sells them for $118 each (unfortunately price increased a bit):
http://www.rockauto.com/en/catalog/b...hub,rotor,1896
4. VHT Caliper paint kit $50 (it's not a kit really, just a 3 spray cans and sand paper) - painted both front and rear calipers (rears painted to match fronts)
Total for project: $1594 (if I bought cheaper front rotors it could have been even less)
Install costs including brake flush and coding: $450 (ouch, but I went for it - I don't have garage and I had little time to do it between exams)
I think this mod improves looks a lot - it makes x5 stand out as not every car has upgraded brakes AND it improves performance (I still need to drive it a lot on my usual route to check it, but I did several stops and it brakes easier/faster than before)