Hey Robbie,
I had the canopy made in Gympie buy Tracwell (
http://www.tracwell.com/) Cobbs uphlstery done my vinyl also in Gympie (
http://www.cobbscustomcovers.com.au/epages/coco16008.sf). The canopy frame is all aluminum, with ally propeller plate roof (keep the weight down) I had them put a extra roof brace in to suit the bolt down points of my roof top tent.
As for dust it's preety good for vinyl sides, I still get a fine mist in the canopy but as my bed isn't in there it doesn't bother me. I have placed foam under my tray side to stop in coming in through there, which worked a treat. In the future (when i get time) i intend to put a vent on the front so it pressurises & keeps dust out, had this on my last hilux & it worked a treat, held out more dust then my mates flexiglass canopy
& as for water never had a drop in it from rain or water crossings. obvisously if you come to a stop in a deep water crossing your gunna get water inside the canopy.
If i was to do it again i would think hard on going to full aluminium doors & removing my tray sides more for the easyness & quickness of getting in & out of the canopy, no zippers or stretch ropes etc. But it adds alot of cost & weight but something to think about. hope this info helps
cheers