Ordered the wheels, tires, axles and innertubes today from Azusa. 6" and 4" AzusaLite wheels for the mains and nosewheel respectively. Not having ordered these types of parts before exposed my ignorance of many things. For example, tires... many tread types, plys, profiles, etc. But after studying their site and catalog for a couple of days I think my best guesses were at least somewhat educated before ordering. I went with simple Ribbed tires instead of other tread types like Knobby, Turf, Sawtooth, etc. Flat profile on the mains and round profile on the nose.
I did not order any bearings with the wheel halves because I am told these need to be replaced with better quality. Will be ordering them from Aircraft Spruce if an Aurora equivalent (or better) is available.
Axles... where to start. I relied on the Forum for guidance here because the GyroBee plans are vague here and simply spec "KB2 Axles". I did order 5/8" diameter solid steel X 8-3/4" long, no step, with a 1" threaded end. From the plans this appears to be the correct length. They are referred to as "Mini Axles" in the Azusa catalog. They will require aluminum sleeves that are 3/16" wall to fit tight. Since they are 5/8" diameter continuously, the thru-holes for the strut fittings will need to be centered very accurately to leave 3/16" of steel on either side of the hole. I'm a little concerned about this detail.
Anyway, that's where the project is at currently.