Buttercream frosting

I believe it would work with any of those! Definitely American & Swiss. I would guess that you can add the raspberries (assuming they're freeze-dried and you'd crushed them up) to Italian as well, probably at the end after you've already incorporated the sugar syrup.

If you're stumped about which one to pick, I would choose based on the flavor profile you're going for! I'm partial to Swiss because it's so light/airy and not too sweet, but if you'd like a sweeter frosting, American could be the way to go!