I'm not a fan of the hydraulic dovetail trailers. It's a steep loading angle and then you're stuck with unusable deck space because you can't carry much weight on the dovetail while in transit.
10K lbs on the tail isn't enough? It all depends on where you put weight on the front...
We have a 35' Corn Pro Custom built for us. Hydraulic tail, hydraulic jacks, 12K axles, and we finally got enough tire on it when we switched to 235/75R17.5 18 Ply tires.
If you don't think what you're building will be heavy, think again...ours weighs 11,800lbs EMPTY. You put 20-25K on it and you know it's there, but a 2016 GM Duramax handles it fine except in steep hills.
AS for the sleep loading angle of a hydraulic tail, yes, it is a bit steep...however, with the extra complexity of a full tilt deck, not to mention the weight, I would think there are better options.
What would I do for loading 2 trucks? Probably build a low pro dual tandem style deck, with a little longer tail than normal and a hydraulic tilt set of "ramps"...but I never minded driving a truck on a good set of ramps anyway.
BTW, we do have a sliding axle Landoll 435...it's nice, but there are nicer options now. Our next one will be like this...
Landoll 900 Traveling Tail
IMHO,
Chris