Whichever decent quality, eight-studded style/make of boot turns out to fit you the best. Fit is much more important than style, and no two different style of boot fit the same pair of feet the same way. Buying footware over the internet is just silly -- it's not like you can upload 3-D scans of both your feet. Go to a well-stocked sporting goods store and take the time and trouble to try on as many different style boots as possible. Make sure you insist that the staff help you get the right fit. It will save you a lot of grief (and blisters) later on down the road.
Any good proper rugby boot designed for forwards will be OK. The backs wear soccer boots to run faster but they have no protection. A tight 5 player needs some protection for the feet and ankles.