God man you could atleast of looked up a few of the millions of threads on this
Keep your runflats if you like the thought of not having to change a wheel or be abandoned somewhere otherwise put on some non runflats. The change is massive, more grip, better ride etc. They are also cheaper, just buy a can of tyre goo and stick it in the back. Ive got goodyear eagle f1 gsd3's and would thoroughly reccomend them. Pilot sport 2's are also good but a bit more. Others include toyo proxes, pirelli pzeros and yokohamas but I cant comment on these having not tried them on a Mini. I did lots of research and found the f1's to be the tyre of choice for more people than anything else on a Mini (just make sure they are german made)...Lots have proxes but I wasnt sure about them in the wet? Im sure others can add their superior knowledge! Oh and I think adding a wider tyre would give you fractionally more grip and also fractionally reduced fuel economy, I went from 195 to 205 and Im happy.