I believe 280's are legal on land...but don't quote me on that. I just know that 220's are legal on dry land and 330's are not legal. For cats, I like natural cubbies made from limbs, branches, etc. with a cedar bough covering the top. I like to build the cubby set with a tree or large bush as backing. I also like a visual attractor such as flagging or a bird feather hanging above the cubby from a limb (use monofilament so that it dangles, blows in the breeze) and I use a 50/50 mix of red fox & bobcat urine at the set. Most of the time I set a good foothold at the door of the cubby, but you could put a 220 there as well. I like fresh baits at the back of the cubby as stink-type baits tend to draw skunks in my area. Remember cats can see alot better than they smell, so make it look like a rabbit, bird, etc. was caught at or near the opening with a lot of fur/feathers scattered around. Cats really like the eye appeal. Cats also LOVE porcupines. I like 1/2 of a porcupine in the back of the cubby for fresh bait. For coons, 5 gallon buckets work great....just cut out notches at the mouth of the bucket for the springs and bait with your favorite coon bait. I like fishy smells along creeks. Just throw the bait in the back of the bucket. BTW...don't forget to stake down or wire the end of the chain on your conibear to a large drag.....a good, heavy limb should do.
A good book or video will give you the best understanding of how to catch coons, cats and fox. I'd look for good books & videos if I were you.
Take care and God Bless,
Rusty