I have the first one as well. This fits behind the side panel (btw, I recommend getting thumbscrews for your side panels if you don't have them already. Murphs sells them or you may find some locally), and is close to the existing fuse block and battery.
Hooking it up is a piece of cake. One wire hooks to the battery, the second wire is close by as well, and the 'switched' power source is designed to hook between the rear brake pedal wire connectors. As the rear brake circuit goes live when the key is turned on, this makes it an ideal place to 'read' when the key is turned on. Again, easy peasy to install.
Running your power from this box to your accessories will follow similar routes to existing wiring from the existing fuse box. And, as this is located next to the existing fuse box, it keeps all of your fuses in one place on the bike.
I currently have both my grip heaters and my auxiliary lights (now broken off) wired from this fuse block. I personally used SJOO wiring for these (I have a spool of it for other purposes), as the black sheath hides itself well, and blends with the existing wire harnesses, brake lines, etc.
My switches for both the aux lights and grip heaters are strapped to the inside of the handlebar 'posts', and nicely shrink wrapped/zip tied, although others often choose an upper fairing location (opposite of the clock or wherever).
