Hi James,
I'm based in Europe, Germany to be precise, own a M20K 231 and recently added a GTS800.
First of all I can only encourage you to install a traffic system. The installation in my Mooney was no problem but I highly recommend to let a very capable avionics shop do it. It's not just about programming, it's also about positioning the antennas relative to other antennas. In my opinion good HF knowledge is required.
Depending on where exactly you'll be you might want to consider adding a FLARM capable device. The Alps, Germany, Austria, France: in all these countries you'll find many gliders in summer time and not half of them carry transponders (or simply don't switch them on). There are even microlights that don't have a transponder but a flarm. I personally can recommend an AirAvionics AT-1 (which may or may not be connectable to the G1000, but they offer a separate small display for it, ATD57). The device, the display and the installation are peanuts compared to the GTS 800.