None of those images look to be a standard print size. You will likely need to get custom sized prints made.
When I need a custom sized print, I use my image editing software and center the image on a white background (or canvas) sized to a standard print paper size.
As an example, your top image is set at 10.7"x4.7" so I put the image on a canvas sized at 11"x 8.5", a standard print size. Like so:
You may even be able to put multiple images on a single sheet of standard size print paper. I recently put 4 images on a single large sheet and my lab trimmed them all for me.
A rough rule of thumb is to charge 2.5x the amount of $$'s you have invested a print. That is not just what you paid for the print but your time, travel expenses if any, a portion of the depreciation of your camera gear, and any other costs.
The size prints are made also has a bearing on what you charge.
It is my understanding the quality of prints made at Costco varies by store.
A popular online consumer print lab is Mpix,
www.mpix.com, and if you click on this link -
Mpix.com - Help - to one of their support pages, you'll find a wealth of info about how to prepare images for printing including
How To Order Custom Sized Prints.