I looked into that a few years ago when I removed and sold my uncomfortable recliner, bed, lounge type LR couch. I only did that research in the event I changed my mind about my RV missing a couch in the LR. I removed the couch and moved the rocker/recliner/swivel over to where the J-knife couch used to be, moved the table over to that side, and than removed the over-the-dash TV, replacing it with a 47" TV on a electric lift between the kitchen counter and the back of the passenger Captains chair where the recliner used to be. I liked the new setup so much that I've resigned myself to not having a couch with a bed in it. But, my point is that there are several manufacturers of RV couches that you can find something equivalent to what you're removing...
here.
Scroll down on their page to find the theater seats that recline enough to use as beds. And you can google for other manufacturers selections too. I don't recall seeing a theater seat setup that lowers all the way into a bed like setting. Mostly just a nearly flat recliner in the wall hugger models.
Not sure what you mean about the jacks. Most jacks have a bracket with several holes where you can mount it higher or lower on the RV's frame. Than of course you can add SnapPads to the bottoms of the jacks and if you need even more height, make yourself some thick wood pads to go under those. Note it's dangerous to lift the drive wheels off the ground so many manufacturers limit the amount of adjustment.