I have the G3X. Here are some things you may want to consider before you close the wings.
-If you are going to use the Garmin AOA pitot tube make sure you have a large enough mounting plate to attach the pitot extension. You also should install the pitot and AOA tubing with plenty of extra at each end.
-I put my magnetometer on the outboard left wing rib. You will need to make a bracket for it. The wiring can run through the rear spar. BTW that location worked great both for the interference and vibration tests. BTW I added two supports to the bracket since this picture was taken, they are triangle pieces that keep the horizontal part from flexing (it had too much vibration during the Garmin running tests).
-Where do you plan to install the temp probe? The wing is a possibility. I put mine on the left side of the fuselage below the horz. stab.