As already mentioned, Otter do it. Depending on where you are in the country, you could also try Divers Warehouse in Leeds/Bradford area, or Hydrotech at Stoney Stanton. (I had pockets fitted from Hydrotech, and they were about £25 each, complete with D rings fitted inside.)
Regarding your neck seal, if you turn the lip inside towards your neck, it will stop rolling, and also "give" with your neck if you look up. Well, it works for me, anyhow...
Hope this helps.
Steve
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