The term "mild deathwobble" doesn't make sense.
Deathwobble is never "mild".
At low mileage like that it could be as simple as properly torquing the various bolts/nuts.
Or a bolt hole might be ovaling out. Once a bolt hole is ovaled out torque won't help.
As to parts and brands, it depends on...
Speed related wobbles and Death Wobble are two different things.
Death Wobble is amazingly violent, it is an uncontrollable back and forth shaking of the steering wheel and thus the front tires, and you typically have to slow down to a stop or near stop to get it to go away. But usually slowing...
Suspension is a matter of opinion. In my opinion, a spacer lift is a spacer lift, especially one that uses shock extensions in addition to spring spacers (like the AEV 2" Spacer Lift).
That said, if that is all you want, the AEV 2" Spacer Lift does what it does fine. It should drive almost...
The Rancho 9000 series adjustable shocks are a decent budget friendly option. But they do have a few shortcomings. The biggest one, if it matters to you, is they tend to give up travel. For a given shock size the adjustable 9000 series tend to have less actual travel. They also have a tendency...
Play in parts like the draglink or trackbar is a really common cause of DW. That play can be in the ends, or even in the bolts used to secure the ends (the bolts not fully tight or the bolt holes wallowed out, often from not being fully tight to begin with).
It can also be from worn out ball...
Uh, define "need". You don't think there are all kinds of fuel treatments and snake oils sold for gasoline?
The reality is, most fuel treatments, for both diesel and gasoline, aren't required. But yet the market for them is huge. I figure it is a small price to pay, and it makes me feel better...
Everyone covered much of the questions about shock brands. But you mention running a 2" shock extension with the shocks from the lift. Are you also running additional bumpstop extension to match that? You need to be. Otherwise your shocks will bottom before the bumpstop halts upward suspension...
Usually for a 4x4 you want the shocks at around the middle of their travel at ride height.
Three options that would help; longer shocks, shock extensions, or remove the spacers.
Unless you have a route that would allow you to swap those shocks for a longer set easily / at little cost, I would be...