Hydraulic tail trailer as a flatbed

I've been considering getting a hydraulic tail trailer.

According to the manufacturer those trailers weigh somewhere between 15,000 and 17,000 lbs.

My tractor is a sleeper cab and it's I think around 18,500 lb.

If I put aluminum wheels on I think I could probably drop it down to 175 or at least under 18,000.

So I think it's possible that the empty weight would somewhere be around 34 or 35,000, which would let me pull 45,000 to 46,000.

Those trailers have a lower deck that is 38 ft and an upper deck that is 10 ft.

Can that trailer be used to run regular flatbed loads or run like a step deck?

How many 48-ft flatbed loads are there compared to 53s?

 

That makes sense thank you.