Yes I was thinking of using Metal Ready then PO15, which sounds similar.
http://www.frost.co.uk/productList.a...frostCat=Tanks
Yes full tank good idea, although the downside is money locked up in fuel that won't be at its best, for what is for most of us, an 8-month lay up.
External protection not a problem really as its fairly well tucked away inside the boot.