If IAF can retrofit F-16 with drappable external tank, they can also make their F-15I's to do aerial refueling with Gulfstream flying over Caspian Sea.
I don't think the IAF needs mid-air refueling for F-15I strikes at iran. The fuel problem is with earlier models of the F-15. I think the Israelis have developed their own F-16 variant capable of ranging over most of Iran.