Help with spring rate

Hey guys,

I’m looking for a new suspension for my truck, 2011 DCSB TRDOR.
I currently running and arb bumper and winch weighing in around 200lbs. I’m look at either the OME with 886 coils, 660lb/in spring rate or the Ironman nitro gas, 824lb/in spring rate. Both lifts are in my price range and I feel will suit my needs for off road capability.
I’m no expert on suspension, so I am a little confused why the spring rates are so different when both are suggest by the manufacture for the added weight up front. I know OME is well liked and tested. I didn’t find a lot on the Ironman set up.
Does anyone have experience with the iron man setup?
Any input is appreciated.
TIA

 

I had 886 coils with ome shocks I got around 2 inches of lift the it sagged about a quarter or more inch. That's with a armb bumber winch steel rci front skid sliders