Those wheels are beautiful!! Seats are a really nice find too! As you say mate, gotta get things while they're available as they don't turn up every day. Annoyingly, I'd spent my months car budget when a set of lights appeared on fleabay
I was really impressed with the spacers. Really good build quality. They're supplied with the studs and nuts to fit but you'll need to supply your own wheel nuts which you've obviously already got with your new wheels. The studs are loose so will need threadlocking into place. Lead time was three weeks for my ones as they needed to be made to order. You may find that he has a set of 20mm ones on the shelf ready to go.