Try Hilly Marathon Fresh Mono Skin socks. They arent the double layered ones, but they have a lovely line of thicker padding along the tops of the toes, which have helped keep my toes happy.
As for your perma-blister problem on your arches Slow Dave, what shoes do you wear? Me and my running friends all have had this problem with Asics designed for over-pronation. Its gone since my feet got used to them (painful up till then though) and I love the shoes apart from this. The above socks also helped with this. And I have recently discovered X-socks ( www.x-socks.com ), not sure how much of the hyped-up technology they claim to have is true, but they are comfortable, keep your feet cool and grip and pad in all the right places.
Hope your sore feet start to feel better soon!