Nike Alpha speed 3/4 D cleat it's quite lightweight (especially for a 3/4 cleawith detachable studs) very sturdy and because of the metal studs it has removable studs it also comes in a lot of colors so you can get your school ones
You can Use Soccer Cleats for rugby or just Rugby Cleats I don't think You can User Soccer Cleats for football Soo =c
I would go to lovell rugby.com
Go to lovellrugby.com its a UK company and takes 28 days to ship to the North America but really cheap soccer and rugby cleats that are top brand names.