IMO body hair only makes a man look manlier, but I guess I am of a small percentage of women. However I understand it is a bodybuilding thing, you want your definition to pop. If you are going to wax at home, buy the hot wax. I have read some awful reviews for cold wax systems. Go to Sally beauty supply and ask the ladies, they will help you. You can microwave it and do it at home. This is the best way if you don't want to be shaving every week or two. I don't now much about nair. The wax ought to hurt, but it lasts up to 6 weeks. Pain=beauty, right?
EDIT: It is said that waxing actually lessens hair folicle width over time, so your body hair would get slightly less coarse and softer every time you waxed.