I introduced myself on the wave page just now. I'm at work and meant to do that. I'm going to be trail riding mainly some rocks here and there but nothing too huge. I still want to have good drivability. It's not my DD by any means but I want to be able to pull some road trips to events. I won't be anywhere near a dessert. I'm looking to fit 37s. I never heard of a mid arm myself, but I've not messed with any JKs yet. They pulled the marketing gimmick on me and it worked haha. I want to be around 4" lift. I'm kinda vertically challenged.
in that case, regular adjustable arms are all that are needed. in order of importance, Front lowers to reset castor, Rear uppers to set pinion, rear lowers to relocate axle to the wheel wells, front uppers. at 4 inches, you will need front lowers for sure. whether you need the rest comes down to preference and budget.
Evo and Synergy both make great arms. the beauty of those 2 brands is that their front lowers for sure allow on vehicle adjustability. as in you do not have to unhook them from the axle to adjust the length.
Evo uses Johnny Joints which are super tough. Can be rebuilt fairly easily with the Currie rebuild press. Synergy uses dual durometer bushings that offer much better flexibility than typical bushings but also the same vibration dampening that OEM bushings provide.
Core 4x4 makes great arms at a great price. I also happen to like Clayton's arms with the GIIRO joint which is the same style durometer bushing as Synergy.
Evo 4 inch plush ride coils are among the softest. but, they will sag with heavier vehicles. I am running Synergy 3.5 inch coils on my JKU and really like them. I ran metalcloak springs on my prior 2 door, but i never cared for them.
at 4 inches, you will need to flip your drag link. there are a couple of ways to achieve this from fairly cheap to more expensive.
your front drive shaft will need to be addressed at some point because you will wear at the CV joint on the factory ds.