It all depends on what you want and how much you want to spend, RC has a cheaper solution, fox has a snap ring kit that works, Halo lifts has tremor specific setups that run from around $1700-$5000, Icon has Tremor specific setups that run from about 2k to 7k, Bilstein has the 5100 series which is fairly low cost, but my choice for bang for the buck would be the eibach set, there's a few different ones, here is one of my favorites.
Eibach E86-35-035-02-22 - Pro-Truck Coilover Stage 2R 15-20 Ford F-150 SuperCrew 3.5L V6 EcoBoost 4WDPair of Front Coilovers + Rear Reservoir ShocksThe PRO-TRUCK Sport Shock is the perfect solution for those looking for a straightforward, reliable damper setup that gains ground clearance, ride...
www.cspracing.com