the above are all good suggestions, but you'll find they will cost as much as a new set of wheels, providing you want to have a good job done. I'm serious; new wheels are very inexpensive these days.
if not, glassbeading and media blasting are your best bet. then have a body shop paint and clearcoat them, to prevent pitting and corroding. for paint i'll recommend ENDURA. it's a two part paint and it dries to a very hard finish. matter of fact, if you paint a car with it, you can dance on the roof after complete drying. Most heavy trucks, highway and off-road are using this paint. also most race cars up here (Edmonton, Canada) are painted with ENDURA. it's a locally made product, but shipped all over the world. as well, one of the two sons of the owner has about 50 BMWs of various types. most from previous decades.