Have done a bit more thinking on this one and decided to fly into SF and out of LasVegas (Flights are from Manchester (Great soccer teams) and via Newark.
I figured this would be less exhausting and give us a bit more sightseeing time.
So no plans made apart from 2 hotel nights in SF and a look round there plus a hotel night in Las Vegas. Did discover that car hire from downtown SF to LV Airport has a 100 dollar surcharge on it where Airport to Airport does not. Worth remembering!!
So come on all you seasoned canyon travellers. Give us some advice on routes, hotels, stopovers etc and help an old limey(well not sure about that cos a Scotsman really) have a really fun holiday