Buying an off the shelf kit isn't very useful, putting you own together with parts from different companies is the best bet and will get the most performance. 4"+ you are looking at about $2500 worth of parts to get the best of the best, mostly due to the fact that 4" is the generally accepted point where you need long arms in the front. You will also need to ditch the front CV driveshaft and switch to a U-joint style, same with the axle shafts.
Then factor in the mileage drop as well, with 33"s you will probably sit at about 11MPG city. Most likely less with the 5.9, I'm getting a good 4MPG more than a 5.9 with less lift than my 5.2. Both hand calculated over a long time.
Don't bother with Rough Country, IRO steering is crap despite being an OTK setup, stay far, far away from Rocky Road Outfitters. Best bet would be to buy everything at once, ship it to MSO down in Montana and save a bundle on local markup and shipping. Many of the companies will ship free in the US and have forum discounts for the US based forums. Probably save $1000+ by picking all the stuff in Montana
If I was doing it over I would build like this.
5.5" IRO coils
Front IRO Adjustable Long Arms
Rear Claytons Long Arms
Iron Rock Belly Skid
Clayton Frame Stiffeners
JKS rear adjustable trackbar
IRO double shear front trackbar or BDS adjustable trackbar
JKS Quick disconnects, BPEs, and shock conversions
Bilstein 5150 shocks
Currie CurrectLync steering
Rear Aussie locker
If you really want to blow some cash, ZJ front Anti-Rock
My build went 2"BB > 3.5" SA lift > 4.5" SA lift > 5.5" SA lift > 5.5" LA lift > 6" LA lift