Replying to Shipping from the EC to Bozeman. What's best/cheapest?

Hi,

So I'm trying to figure out what is easiest/cheapest in terms of moving my shit from the Netherlands to Bozeman next year where I'll be studying. I simply can't take everything with me and I'm wondering what would be the most cost efficient way to shit a large suitcase/carton box to Bozeman. I was thinking of taking the extra stuff with me on a plane and then having it shipped from NYC to Bozeman with some American company. What copmany would be best to use? Fedex, DHL, UPS? I'll be ariving early juli and will be heading to school in Bozeman somewhere end of august, so I also need some additional storage in between that time.

Who can help this Euro guy out?

Regards.