Can't speak for the uncertified kit, but equally would be suprised one would put the rather pricey Sandel into a plane which doesn't need expensive certified kit.
The Sandel 3500 looks nice - I had a play with one recently.
With this kind of avionics, one important consideration is integration with other systems.
For real long distance touring I would put in a decent IFR GPS, so you get nice features like the OBS mode (great for flying DIY approaches and other stuff).
Are you putting in an autopilot? That's really vital for touring.