I'm getting ready to mount my 19's, went with non-runflats. Slime actually makes a kit that has the slime, and a small compressor. Kinda like an "M-mobility kit" if you're familiar with that. Only it was only $25 from advance auto! The mobility kit from BMW is $145. It will work on punctures up to 1/4". On long trips I'll take one of my take-off 17's.
http://www.slime.com/smartspairs/