There are a couple active members on here with TJs.
Wheel wobble is pretty common on TJ's, especially with M/Ts.
Get the tires balanced, and see if that helps. After that look at your alignment, TREs, etc.
There are NO worthwhile mods for fuel economy.
Performance gains are not large enough to generate any significant power... Waste of money IMO.
The edge trail jammer gains are disputable, with many people not seeing the same gains. But its $1000 for an air intake that will be more susceptible to sucking up water, and a bored stock throttle body with a larger plate... IIRC it does have a smoother flow to it, but it is only like 2-4mm larger than stock.
So 1k dollars buys you a disputed 21hp... When people are swapping Dodge 5.2/5.9s and GM gen III/IV V-8s for a little over 2 grand... I know where I am going to spend my money when I want more power.
Rustys stuff is mostly crap. Poor shocks, and springs that sag.
Lift crap:
First off, do not buy your lift from Quadratec/4wheel parts, etc. If your not already on Pirate 4x4 or Jeep forums, join. Go to the vendor area suspension section, and look for threads with vendors advertising the lifts you want on sale. These vendors are much cheaper than the Quadratec/4wheel parts, and will compete with each other.
I have 4 x 2.25" pucks in a box I will give you for $20 bucks. You will need to buy longer shocks and adjust your bump stops.
I would not recommend a budget boost just because you can buy some springs for not too much more. (when buying new) I bought a BB and ended up replacing the pucks/stock springs for OME springs because the stock springs sagged. Replacement springs can be had relatively cheap, and can possibly give you a better ride, will offer more travel, etc.
Rubicon Express makes some decent kits for the money. Stay away from pro-comp, and other cheapos. Other recommended kits are BDS, OME, Currie, Clayton, and a couple of others.
Anything over 3" will require a transfer-case drop or a 1" body lift and 1" motor mount lift, or a SYE and a drive shaft. Anything over 2.5" generally requires at least an adjustable rear track bar. A 1" body lift will also help you tuck your gas tank up higher, as well as your transfer-case.
Most cheap lifts take short cuts when it comes to bushings, spring/shock quality etc. Stay away from control arms with poly bushings.
Do you have a manual or an auto? Wrangler Xs came with the D35c, which will be fine on 31"s as long as your not an idiot.
If your going to wheel it the first things I would say you should do is:
Home made disconnects
Rocker guards (fabricated, or purchased)