Looks like 4 questions...
Sway links? Did you lower your jeep? Why do you want srt8 swaylinks?
Rubber is low maintenance and comfy. Polyurethane is performance for the street and needs lubrication or it squeaks.
I select my order based on need first (replace broken stuff first) and cost second. I was gonna do swaybars, links and bushings first, but a deal on springs and struts fell in my lap. So I'm doing those first. Sorry, no real logic here.
I switched my tires from 245/60/18 to 255/55/18's. Same overall height, no problem. More grip, steering was slightly stiffer, but got used to it fast. Your selection will be a bit taller. Generally, larger tires reduce acceleration, mpg and braking. However, most tire stores say +1 size is OK? And lots of people put MUCH bigger tires on jeeps all the time. So...?! Your speedo and odometer will understate your speed and mileage by a small percentage, so a reprogram might be needed if you are concerned.
Boring regular tires that last like 60000 miles, like the forturas that the jeep came with are good for mpg. Go to tirerack.com and look up what fits and read the user reviews. Honestly, how you drive affects mpg more than the rubber though. And the correct tire pressure can be very useful too.
Hopefully this is of some help. Even if is six weeks after your original post...