> to integrate the security that a strong typechecker can provide

Have you checked out typed-racket? That's a reasonably nice way to get strong typing by tackling type correctness contracts on top of otherwise standard racket.

There's also Alexis King's marvellous Hackett, which seems to be finished for now, but was positive proof that you can have - and eat - all the curry-flavoured cake you want while staying in scheme.