I researched the 70mm film system for Hasselblad a while back.
1) No one has made the film with the necessary and proper perforations for years.
2) Assuming that you could find the unexposed stock film, getting someone to make the perforations at a price you can afford is less than impossible.
3) Finding someone to process the long film rolls is a life long search without success.
4) Finding the tanks to process the long film rolls is probably extremely difficult at best.

Other than those problems, it will be clear sailing.