Unless I am very much mistaken, you'll have a type rating to fly the turboprop. It just won't be the 737 fo course. Personally, I'd go for the turboprop rating and the 400 hours because that would mean you have a job. You'll be gaining hours etc while the 250 hours and a bare type rating on a jet doesn't mean *that* much.
Hours and experience on a multi crew turboprop is a great start to your career.