Punto has the stuff you need it's in the sale section.
The main and overall bonus to twin battery setup is that, provided you maintain 2 good batteries you'll never go flat by accident.
Imagine if you went to do a bank raid and you left the lights on
that could be embarrassing, especially when you have to explain to the wife and kids that you, Charlie and knuckles are doing a stretch in the klink
The above scenario generally can't happen on twin battery system.
Down side is that when the front battery dies, you have to rely on your Jedi powers to spot it, usually tell tale faults occur tho.
56 350 2.2 130ps mk7 with 2 side doors
65 290 2.2 125ps custom with 2 side doors
07 350 170ps
Ids v86 licence + v86.04 update + xprog
hereIds map
here