60's Birthday Cake

Next July I will be 50 and my brother will be 60 2 months later.
I was talking to him about our party and we've both agreed that we want a 60's
cake. We suggested on one side, a picture of each Beatle as they were pre-Sgt
Pepper, and on the other side of the cake one of John Lennon's poems. So a:
what is the likelyhood of this being possible, and b: how much would it cost?
The cake would have to be probably 16" square, so each Beatles picture would
therefore 4", and I would insist that their likeliness be spot on. This is the
perfect cake for us, it would be sponge with jam and cream as neither of us
like chocolate and we loathe marzipan! What do you think????