Official Luthiers Forum!

I think that commercial veneers are the same thickness that you want. Just check one of those sites.

I think bending both sides at once, one above the other, is a good idea...

For prebending the veneer I would be inclined to put the blanket against the block form and the veneers above it (with or without a slat). If you get any scorch marks on the veneer you want them to be on the inside of the side and not have to be sanded out. The slight bit of "oversize" caused by the thickness of the blanket can be squeezed out by the clamps or vacuum bag when you laminate them together.
When doing it this way I use a couple of spring clamps to hold the blanket against the veneers.