Easternbeaver has a full kit with the PC-8 fuse panel, relay and "mains" fuse. This fuse goes in the main feed wire and must be installed close to the battery to protect the high current wire. Like all of Jim's Easternbeaver stuff, the PC-8 is top notch quality. We particularly like the post and nut mains connections on the PC-8. You never have to worry about power loss due to loose mains connections.
Another option is the Fuzeblocks FZ-1. http://www.fuzeblocks.com/index.php
The fuse panel is about the same size as the PC-8 but has the relay built in. You still need a mains fuse in the feed wire which is not supplied but fuse holders are readily available at autopart stores.
The FZ-1 has a slick fuse setup that allows you to choose whether a circuit is direct wired or switched just by moving the fuse from one position to another. There are three rows of fuse sockets. Put a fuse between the center row and the left and it's direct (they call it constant); or between the center row and the right and it's switched.
Another nice feature is built in diodes to protect the bikes electronics from transient voltage spikes. This is particularly important on CanBus systems.
One thing we don't like about the FZ-1 is that the relay is soldered in. This is good news bad news. The good news is that it makes for a robust connection and low profile. The bad news is that is has to be de-soldered to replace it if it fails; not something you can on the road. Automotive type relays are typically very reliable but nothing is perfect. There is a work-around if the relay fails out in the boonies. You can swap the fuses over to the direct side to get back to civilization but you have to remember to switch off any accessories that were changed over when you shut the bike down.
We just purchased an FZ-1 for our new 990 Adventure. We haven't installed it yet but we'll let you know how it works out.