There are several lined JK's. It's a bit more work due to some goop Jeep put in the tubs, but still more functional than paint and looks better
I suggest U-pol Raptor liner, had it sprayed in my TJ, but it can be rolle/brushed as well. Not too aggressive in the grit dept. which makes it much more livable than some others. No skinned knees and elbows if you rub up against it, but it's not slippery either... Monstaliner is another popular product.