Nice wheels !
I personnaly like the Monaco.

For the flared fenders, they are worth it.
Bought my 20" without them, and I disliked them.
Installed the flares since, much better.

For the tires, go with what's used by BMW:
275/40R20 F
315/35R20 R
Wheels, 10" in front, and 11" in the back.

Run Flat tires or not, that's your choice.
If you go with non-RFT, get yourself a car club card for the towing, or purchase (thru E_Bay), the spare tire kit.
This one goes in the floor in the back, if you don't have a 3rd row seat.
If you do, Car Club card or either Continental or BMW instant puncture repair kit.

Post pictures when it's completed !
You will sacrifice MPG, but if you're going for the look, it's worth it.

__________________
2010 X5 35d Black - Full (current)
2012 X1 28i (retired, won't be missed)
2007 335i sedan (retired, and missed)