Hi guys my first post so be gentle with me

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I have just purchased my first mini a 2003 52 plate cooper s fitted with 17 inch rims and run flat tyres.One of my rear tyres has a slow puncture and needs inflating every few days.
Can anyone let me know can run flats be repaired, can I change run flats for non run flats if so do they all have to be 1 or the other.What are the benefits of either t yre and can anyone reccomend where to get the tyres.
Thanks for any help.
Cheers