These guys are in Alberta, and do some Aussie style work. Their background is in the trucking industry, and this is a new endeavor for them. To me that means they know how to build tough stuff, but to others it may mean different. Plan on spending $20k on a flatbed from any of the vendors by the time you pay for the tray, shipping, installation, etc. It adds up quick. I'm having these guys make one for a Ram with all the bells/whistles minus a headache rack. i.e. boxes, water tank, drawers, etc. All in, to include having it sprayed with Linex (personal choice, not required) I'll be around $16-17k. That is fully optioned tray, shipping, local handling/spraying for Linex, installation, taxes, etc. He quoted a tunnel box too, but I didn't have the dimensions of the camper at the time. He had an aluminum canopy style camper to sit on top of his demo tray just like the Aussie style you're likely looking at.
I stopped by the booth and spoke with Ralf (I had already sent a deposit on a tray, so this was a bonus for me), got to see his product first hand. Very impressed to say the least. I have a background in industrial design, and asked a lot of questions as to the how/why. When you design any product, you have to make choices, and I just jelled with his reasoning and thought process. Then got to touchy feely may way around to see the actual product to see how well they could execute an idea. He had all the CAD info from Stelantis on my truck, builder's guides, mounting points, etc. I printed this all for the installer, and he has already built it into the design (first tray they designed for my specific chassis). My guess is that once they get a foot hold, pricing will bump up to the others out there. I am not sponsored, subsidized in any way by them. This is just where I ended up. During expo West he was projecting work being completed in October. My guess is that lead times are longer since the show. Many of these companies are booked, some as much as two years out. The times we're living in I guess.
Summit Expedition Trucks:
https://setoverland.com
Others in this field you may want to look up include:
MITS Alloy (Nice stuff)
Norweld (kind of the OG when it comes to bringing this style tray to the US)
Bowen Customs (super nice work, but get in line)
OEV Alumatray (Not the flashiest, but very functional features if you're looking for them)
Highway Products (established, also from the trucking industry)
There are more, but those are some of the many I researched before going the direction I did. I also looked at all the normal American farm/ranch style companies such as Martin, CM Truckbeds, etc. Definitely cheaper, but there are a lot of comprimises built in that you have to account for when evaluating the price.
I don't have the truck or tray yet (tray is due in by late July), truck is well...who knows. So no final pics to show just yet.
Best of luck.
