Nice rig. Got any sewing friends? A cabin tent of your choice with an adapter tunnel from your rig to the wall of your tent. You could put some snaps on the bottom rail of the roof rack to attach the top o the tunnel and use bungie cords to hold the bottom, along with 2 cords to hold the doors open. You could add some magnets to keep the tunnel tight along the vertical sides. That way the only mod to your rig is the snaps add to the roof rack. The adaper tunnel should be large enough to be able to close the hole in the back/side wall of the tent. You could also do magnet no-see-um screen to cover the rolled down windows.
I'd get a tent that will take a wood stove just in case you want to push the seasons. There lots of designs made from like 20mm ammo cans. I just got a single pole tent 2-4 people <$220 and a small titanium wood stove for about the same price , <#15 total. This was for the 4 wheeler or the rickshaw trailer for the mt. bike.
