Wiring accessory's to battery(?)

Hey All .
Does anyone have experience with hooking up a pigtail and running Gerbings heated gear from the battery to the troller?
Also I'd like to run a USB charger for my GPS and iPhone/
Any suggestions or prior rigging? Also, would it be recommended to upgrade the battery if I'm using al this on a distance trip?
I see all kinds of battery options out there....

I am in the middle of this with my 04 KTM Adventure, but it's much the same as my 08 KTM SD. Girbings makes a fused pig tail...$10 USD. I will connect the + to the starter solnoid and - to the motor ground. I am looking at adding an additional minifuse box, Aerostich # 4758, $12 USD. It is a four fuse box with water tight cover. Wire in a Girbing connection to power the fuse box. When you want to charge your batt, disconnect this quick disconnect connection and use it for charging. Wire in the the Girbing connections comming out of the fuse box for your additional gizmoes, color coded for the different fuse ratings in the fuse box. For the heated grips, I want them switched thru a relay, Aerostich #4667 $4 USD. I got in a hurry with my Tiger heated grips install with no switched relay and drained the batt too many times...4 times, what a PITA ? Way too e-z to leave the switch on after the ride. And yes, it will drain the batt so the starter motor will not spin up. The Aerostich catalog has other options dependent how deep your pockets are. Auto Switched Relays $ 25 USD. Power Distribution Module $149 USD. Auxiliary Power Fused Panels $58 USD.
http://www.aerostich.com

There are two accessories connectors in the headlight console thingy.