Hi,
I highly recommend keeping the two projects separated in your mind. Dual battery..... Then Accessory system.
People get too confused when discussing both together. Both can be simple or confusing.
Dual battery
Most go with the TrueAM isolator. I can hook you up with one here -
TrueAM - Isolators
Use code HONDASXS10 for 10% off and free shipping on TrueAM products.
Then, once that's setup. You need to build your accessory system.
Lots of good ones and 100 different ways to do it.
@BBLASER just posted one great one.
I'm more of a simple guy and went with this one of these -
PDM60 - Rowe Electronics
But, I would choose this one if I did it again -
Amplink | Rowe Electronics