Don got yer thexy pannies in a bunch you thexy tall stu...yeah ok, sorry, but 5'9" can't be considered tall.
Yes, 3-4K to make it useable. Sell the crap you take off on Craigslist or flea bay. List it on here too. That'll help cheapen it up some. The Carli suspension will make you wonder why you wasted the money on the RC for aesthetics. Even if you throw the crap in the dumpster, you're still at least $6k cheaper than another truck, and probably closer to 10k cheaper. Then you get to pay insurance on the extra pickup all year after paying the State of Texas their percentage. Pick up some platinum rims for not more than $800, some 295/65R20 tires (for high load rating and they are basically 35x11.5) for 1600, Carli front leveling kit for $910, rear Bilstien shocks for 160, and OUO or PMF traction bars for $850-$1200. That's $4600, if you don't need the adjustable trac bar you can knock about $345 off that, but then you get to sell your current lift, rims, and tires. I've absolutely no idea what they are worth, but if you can get 1600 for all of it, you're at 3k. No way in hell you can buy and maintain a second vehicle for that. A second truck will cost you at least that assuming you keep it 5 years and sell it for what you paid....that's if it doesn't break.
OBS - old body style.
Certainly do what you want. If that's keeping your 37s and buying another truck, go for it. I just find it a bit silly to pull with a lower powered, higher mileage, older likely less reliable truck, than the one that fits the keys currently in your pocket.