Cermag will make double thick bars too; though they're also in England.
They have been very accommodating about small batch custom orders.
Even though ceramic spacers aren't listed on their site, they probably would make them if you can't find another source
Good call. I'll probably ask them. Looking to make or buy double thick alnico spacers. I want to undertake a project whereby I get a PAF set to balance volume wise. I would put 1 regular thickness A3 in the neck and then load up the bridge with 3 double thick mags! I think it would work!