Im 21 aswell and having my MK1 on classic i got the best deal from adrian flux but had to knock them down quite a bit.
Not sure how much the insurance woud go up for the SC as my daily is a 2.0 MK2 and isnt much different insurance cost wise to the mk1 when i was running it as daily. Problem with a SC is finding a decent one for a reasonable price.
I would say if you find a nice 1a then go for that as they are a bit more uncommon than 1b's