Spare tire for larger brakes (4.6/4.8 is) question.

[RFaber]

I have a question regarding the spare tire used for larger brakes (the 4.6is and 4.8is). The spare I have in my X5 is a 17" alloy spoke rim, Its a stock style rim, not a temp spare etc. It fits on the rear wheel of my X5 (with the 4.8is rear brakes) but not on the front! (at all!!!) I have stock 18" rims that JUST BARELY clear the balancing weights !!!
my question is to the guys running the larger brakes. What do you have for a spare tire!? I saw this on realoem,
01 Emergency wheel, light alloy 5JX18 ET:40 1 36116750316 $203.95
and was wondering if this is the spare that fits the larger brakes!?
my next plan is to find it somewhere! lol, for now I have told my wife, if we get a flat up front, ill have to jack up the X5 and put the 18" rear wheel up front, and the spare on the rear wheel, until I get it repaired.
I like to be somewhat prepared for the worst ! and think that now that I have these monster brakes up front, I should have a spare that could be fitted if needed! I would probably put an emergency spare on the rear anyway, (steering is priority over rear wheel power and handling in my opinion. !) but I was just looking for a solid answer from the forum.
I don't suppose all the 19" and 20" wheels are utilizing run flats! ??
Thanx in advance!
Riemer

PS, calipers are since powder-coated royal blue, and the tires have been changed! (this was a test fit the day I got the brakes sent to me