Just to let you know, at the moment there are no arenas in the UK capable of running heavyweight spinners. This wont stop you from building one, you just will have to run with a deactivated weapon at all events.

As far as I know there are no plans to build an arena capable of running spinners. There are two arenas capable of running featherweight spinners so if you are set on a spinner maybe go for a feather first.

But I would go with a disk as they suffer from less air resistance so spin up faster and have a better top speed.