Codecs can squeeze a few bits here and there, as can lowering the already-low frame rate. But the main problem is the "reasonable size to transfer" and the 800 pixel width. That is a big size for a 'portable file'!

A television screen of 640x360 would be 2/3 the bytes (12MB), large Yourtube 480x270 would be 1/3 (8MB), and original Yourtube 320x180 would be only 16% (4MB) the size of the 800 pixel width.

Alex - a lot of this is going to be a learning experience. Every shop does things a little different than others. A lot depends on the material(s), the scale, and the complexity; it depends on what and how you want it made.

But the most simple and obvious start point is to export a 3D DWG of your model from SketchUp, email it to them, and then get them to review the file with you.