dry weight of 12,500
With a dry weight of 12,500, even loaded with factory options, you'd need to fill ALL you water and grey/black tanks to max at 18,000.
I'm towing a 37 foot Alpenlite 36 Stonecreek RL, triple slide and both truck and trailer gross at approx 22,500. Thats with a 100 gals of fuel etc.
I have plenty of power and stopping ability, but would prefer to be legal.
the new Dodge 03 3500 has a CGVW of 23,000 which is nice.
Also bear in mind, Alpha may be giving the GVW of toys inside also, with water etc etc. Ask more questions .
If you plan on packing it with 3000# of toys, well look at bigger trucks.
PS: If you go to medium duty size trucks, check the semi paper magazines( at truck stops for free) out for some great deals. Saw several rigs for less then 20,000$ which would be ideal for a medium hauler.