[Arran]

Something isn't right there, all three should have an option other then two day shipping. The USPS has a website that allows you to look at their shipping rates, usually all you have to do is type in the destination and the weight, if that doesn't work then they have a page with service tables on it, they also have the option of buying postage online, but not with all services. Probably the best option for heavy objects is to ship by bus if you can, less transfers, or loading and unloading of packages. Here is a Fed Ex page stating that they have ground shipping, have you looked through it, sometimes the guys at the counter don't really know anything or are just trying to up sell a more expensive service.
 
https://www.fedex.com/en-us/shipping/ground.html

Regards
Arran