Dont listen to those chodes at 4 wheel parts. I went in there asking about ship times on icon stage 4 for my truck and the guy tried to argue with me that they didn't make that for my truck (11 Ram 1500) because it has leaf springs. (It doesn't. And the truck effing rocks with that stage 4 suspension in it...)
I like my KM2s, I also like the cooper discoverer stts. But for crawling, and lasting, I would go with the KM2s. I have no personal experience with Toyo, but have heard good things.
Now, as to size...IF you are planning on moving up to 37s, you should also plan on doing some revisions to your radius arms... See for example Alpine Spirit's rig on Ronin Wheelers. Grandpa X can speak on this with way more competence than I can, I'm just passing on what I've heard, and that is the Calmini kits aren't designed to handle the bigger meats.
Here is a quote from Casper on an older thread, re: Broken radius arms:
"This has happened to a lot of us. It's what happens when you build the kit for other then what it is designed to do. i.e. bigger then a 33" tire, not running a sway bar to limit the articulation etc, etc.
In a radius arm design there is only so far you can flex before it binds. Once it binds up, something has to give. If the weld one the drivers side mount where it's welded to the cast isn't perfect then that usually goes. If that weld is done right, then the upper arm usually will snap. There are several ways to get it to go further. On a hard mounted upper arm like ours you need to have one of the arms "wristed" (I think thats the term they use) where one arm will be un-pinned near the axle to allow it to pivot when the axle goes up and down. The other more common way is to not hard mount the upper arm and have joints on it where it connects to the radius arm. This allows it to flex more. There are different schools of thought as to whether or not you should "inboard" the upper arm or not. Kevin's arm is not in-boarded, mine is. Both flew very well.
Should be an easy enough fix Eric, just need to decide which way you want to go. I really don't think Calmini will do anything since the kit is not installed on your truck as it was intended to run. But give them a call and be nice. They are always willing to work with folks who don't go off on them.
Feel free to contact me if ya need any help.
Cheers,
Josh"