All of the surviving F-117s are stored disassembled at Tonopah in the original hangars from which they operated, and the USAF has not offered them for export.  It doesn't really make sense from a political point of view that the U.S. would ever sell them to Israel anyway, since they are a purely offensive weapon.

 

Even if they were available, these aircraft wouldn't make sense for anyone to buy and operate.  They are extremely expensive to maintain, and there is no longer any logistics chain for them.

 

They have fairly long range and are air-refuelable -- in fact F-117s hold the record for the longest single-seat deployment (flying nonstop from Arizona to Kuwait in 1990), and they can carry weapons like 2,000 lb LGBs and bunker busters that would be among the weapons of choice for targeting buried nuclear facilities.  So they could carry out the mission you envision.

 

But the Israelis will have to wait until the F-35 is available before they get a stealth aircraft.

I understand that it would be very difficult to get the planes back into service, however, if there is a country that would be willing to spend the time and money to get the capabilities out of the aircraft, it would be Israel.  I doubt anyone but a select few would know about a transfer of aircraft even if it did happen.