Shock recommendation

My wifes dd is a 2003 suburban. We bought a 1996 four winns 20 ft sport boat in 06, and going to the river is about 300 miles. Towing the boat is a dream with the burb. So last year the wife and kids ( adult kids ) was complaining about the ride (not towing ) and as i had never replaced the shocks before i replaced them with some ranchos which are not heavy duty enough. Now the burb lowers when putting the boat and payload and actually rubs on the inner fender well. Im not asking you guys what i can do in conjunction with these i just i would rather buy and install a heavier set of shocks .
Boat 3100lb
Trailer 800lb
Max trailer weight 8400lb
GCWR 14000lb
What do you guys think ? Thanks in advance.
I know how we love photos so im throwing one in.
Gary 20180613_150216.jpg