We do offer
universal struts but they are more intended for people looking to go lower. I would honestly suggest possibly visiting an expedition forum as well as looking on here. The Expeditions have some very specific quirks with their suspension and you might get some of the hidden tricks from a community focused on those in particular.
You can reduce the hitch weight by transferring more of the weight to the rear of the trailer, however you will want to be careful not to overload the rear trailer axle more than the other. I would suggest taking your entire setup down to the scales and get some realistic numbers. You can also go for a couple of measurements and see how moving the weight around on the trailer effects each axle weight distribution.