Most of those suitcase nukes would need a fair bit of work to prime nowadays to be honest, whilst the bomb may still be 'live', the half-life of most detonators is only about a decade, so I suspect those suitcase bombs would, even if Iran had one, be in no fit state to use without work. Though, yeah, I agree that sounds more like 'bloke down the pub' stuff.
I don't think Iran would be crazy enough to do something like that with a missile either, I don't think he has a missile that could penetrate Israels' Air defences anyway. Rockets are one thing, but Israel has Patriot systems or the like iirc? They can't deal with Rockets but they've proven to be very effective against the older, larger missiles. Besides, this time you'd know which direction it was coming from.
To be honest, if he was crazy enough to try this, I think you'd be surprised at the rest of the Middle East's response.