Well, in my business I ship smaller items to the UK, Australia and Canada every week. Fedex is always cheaper than UPS. The limit on USPS I think is 130 inch circumference + length and about 70 lbs. Ask the vendor to price yours in multiple packages that each are under the limit. The bumpers may be a problem but everything else should work. The catch is that standard boxes may not be available that are under the limit but big enough in your longest dimension. I often 'cut and paste' boxes to do this for my customers.
You can check pricing on the USPS web site.
