acabgd

A couple of sites that may be of interest are:

www.seatguru.com which has seat maps of most major airlines.

www.airliners.net - go to the Photo search engine and look for cabin views of Boeing 747 (any type)

You are right to have identified that it is the upper deck that makes the 747 special - and I think the confined space of the upper deck - housed in a bulge - makes the 747 look way more impressive than the A380.