newbie has some questions about a 99'

hi, i'm new to the group, and i've been lurking for awhile now, and i have a question. a guy at work has got a set of aluminum rims from a full size chevy, 5 bolt, 15"x7". can i use these rims? i need new tires, and i'm thinking about going with bfg at's in 30". i have a 99' 4 door 4x4, no lift. also, what kind of plugs do you use? what about a power chip? i just changed out all fluids, and had the dealer flush and filter the tranny. the truck has 66kmi on it. anything else i should worry about? i only use a trailer occasionally, and a small one at that. i do go off road hunting in the fall. thanks for your time.