disco ser2 dual battery

[colrospeake]

I have a disco series2 1999 and I am installing a dual battery in the rear of the storage area, in the dicky seat area. I have a digital redirector for current after the starting battery has charged to 13.6v and then the charge goes to the dual battery. Easy as when you look at the situation?. I intend to run a 60 litre Weaco. I have loads of space so what battery should I get.
I have been looking at a 102amhr AGM battery. Any comment would be helpfull.

[Slunnie]

I would get the sealed AGM with the most AH as you can get and want to pay for.