Those springs rates seem really high, especially for a constant rate.
I’d look into progressive rate springs or air bags. Those will be too heavy for DD, my opinion. I’ve got a built 08’ too, and I pull an off-road trailer.
If you can swing it, do White Rim in Canyonlands. Pretty secluded campsites. Pretty epic, did it in 2015 with my then 1,3,5 yr olds + wife. We've been doing a summer overland trip every year since. Ive found that stopping at random playgrounds along the way helped with the long car rides...
There were plenty of times I wanted to throw one of em out the window ;). But worth it in the end. Memories I hope these kids remember when they've got kids of their own.
Thank you. We did another trip the following summer but this time we pulled a trailer with an RTT on it. Made things sooo much easier. Trip report here http://forum.expeditionportal.com/threads/161612-2nd-Annual-Family-Overland-Trip. So much to see in your neck of the woods!