Contact Skyway and tell them you are a First Team looking for 8" wheel chair wheels they supplied to first. They should be able to help you from there. If you are using the KOP frame then 3/8" grade 8 bolts work good for axles. Tell skyway you want bearing for the axle diameter you are going to use. They sell good bearing with the wheels for a reasonable price. IFI doesn’t have the wheel sprocket adapters listed any more. They were expensive. Last year we got a piece of 3/4" LDPE from Mcmaster. Used a 3" hole saw and I believe a 1" to make the donuts. Put them on the wheel hub and mark the spokes in the six points. Use a thick saw blade to make the slots. Get aluminum sprockets from IFI or AndyMark. Center them on the donuts and drill the mounting holes. Use 10-24 socket head bolts with NYlock nuts. Thats what we did last year.