BMW: Advise on Run-Flats needed

I'm planning for a new E60, but am unsure about the run-flat tires/rims.

Sure, the car will cost $50k, but I still don't relish replacing tires for
over $1000 (I expect to be a bit carried away in the early months & probably
won't get the best tread life).

My question is this: Can the run-flat rims SAFELY and properly accept NON
run-flat tires, or would I be stuck having to replace with run-flats
forever?

Go ahead & call me cheap, nuts & anything else you like, but I suspect I'll
still get the sports package and special order regular rims.

> And don't ask the BMW dealer if you can fix a flat, mine promptly stuck 

Gimme a break! I wondered if they expected one to drive to the nearest
dealer for a replacement in such a case. Not an option. What if you're
driving cross-country & end up in Tuba City? Sorry, but run-flat gets
plugged in such a situation.

In Leonard's response he indicates that the manual OK's replacement with
regular tires. Fine with me, but then what do you do if you get a flat?
With the run-flat option, you don't get a spare!