I used all (except the front camera) BMW Euro parts and ordered them from Rover Active (eBay). Here are the parts that I got:
BMW ACM: 65500441372 - $750
BMW Back Camera: 66210412010 - $650
BMW USB interface: 65500433281 - $450
Switchbox: 66210406999 - $450
Front camera Wiring set: 66210411384 - $60
Front camera Bracket: 84210305664 - $15
Front Camera (not BMW) - $230
Battery Tender - $40
The part prices changes due to exchange rate.
You don't need to go to dealer for any code change or software update, as long as you have AUX in already. If not, it will require a code update. If you have a 04 E60, then you will need a different CAN bus.
I checked out NavTV before, but decided to go with BMW ACM since it is all integrated with iDrive.
We tried BMW Round Vision ($2350 - a whole kit includes ACM, front/back camera, switchbox and all cables, but no USB interface) on Michael's 545i, but we didn't like BMW's front camera. It is point to the 2 sides, like Eclipse's FEC106 camera:
ECLIPSE Side View Camera FEC106 | Fujitsu Ten
I want to see what is in the front, not the 2 sides at the front.