Insulation wise I'm thinking the foil roll stuff with the one furry side. Or the spray on stuff that Steve Green mentioned. Need to source who does it though....
Daz
Why dont you use the coolroom panel inserts that myself & Tony have used?
They are easy to work with, around 50mm thick and work a treat, best of all they are FREEEEEEEEEEEEEEEE..... A coolroom place in Malaga have them and are more than happy to give them away.