if using a trailer, all IRS rear suspensions will have more SAG in them when you add a trailer to things, its by there design,a nd then you loose ground clearance as loads get heavier, a solid rear axle , will have less ground clearance to start with, but stays the same with a load
Both designs, handle trailers pretty well, , pending size of atv itself and well, load in the trailer and also keep in mind HOW heavy the trailer is empty
MOST atv's have a LOT more power to PULL a load that stop and control it, its very easy to have more weight behind you than you can safely control
on level ground, its amazing what a small atv can move, but add in a hill and watch how fast things can get scary
My small honda 400 foreman, (geared super low) I have towed over 4,000 lbs with countless times, I have even loaded over 1500 lbs ON IT, I have been pretty hard on this atv for 20 yrs and still runs like new
but when towing a heavy load, , say 1500-2000 lbs, at any hill, if I wanted to STOP mid hill, or have a turn , it can jack knife me if I am not REALLY thinking ahead on what I am doing
as for a recommendation for you, IMO the two most reliable atv brand out there are Honda #1 and well Yamaha,#2
the work side of honda's will be the foreman and then the honda rubicon
of the two there both very capable at hauling loads out of the woods, but again both are limited to what there brakes can control, more than them having the power to pull things behind them
from Yamaha, there wolverine and Grizzly line up is a great all round atv, more play than pure work, but due to they can be had in larger motors (550-700's) and IMO having the best CVT system out there
they do work well and offer more options and things for less $$$ than what honda offeres
IF where ever you go has wet slippery or muddy terrain, I'd make sure what ever atv you get has a locker, to PULL a trailer with a load on it safer!