If it were me, I'd just use all schedule 40. Get a couple more T-s and butt them up against the ones you have so that you can put a cross bar in near the centerline.
China/Harbor Freight $3.69 with coupon (10" pneumatic), 5/8 X 5" bolt for axle, four tee's and One 10' X 1.5" PVC. I am still thinking of using small screws for connections vs. gluing. I want to make it collapsible for compact transport.