I tow a lot too...
and you want lowered springs?
I‘d have thought a better approach would have been some well engineered airbag system to adjust ride height along with adjustable shocks to provide more damping when you are loaded…
One of the Subaru sti’s editions sold in England had complex airbag suspension systemwhere ride height and effective spring rates were independently adjustable along with electronic adjustable shocks… rather cleaver by all accounts… It was a have your cake and eat it too solution, though I imagine it would have been costly.
No idea what the current state of play is with air suspension systems but something to consider while looking at the Audi in the video below
Just keep in mind that quality suspension isn’t just springs, it’s spring rates, dampers with compression and rebound damping matched to the springs along with bushes and such…
If you are looking at struts and all that is of interest is SSL’s, then you are missing the point…
Not intending to be rude but it‘s probably better to go to a quality suspension retailer and explain your needs and wants and have then create a package for you, maybe take you for a drive in some of their vehicles? It’s going to be more expensive but you should have guarantee
Buying stuff, presumably privately on the www, isn’t going to end well if you pick the wrong s
ring/damper package that someone just wants to offload and then have to find someone to install it. Guess I’m saying if you have to ask questions like “is there anything missing here” you probably need more than what a forum can offer…