Choosing the most optimal story size for 14'' and 23'' target screens

Hello, 

I am creating courses for several certification programs and I need to find the most optimal story size. Target devices are Dell Latitude Laptops of 14'' and Dell Monitors of 23''. 

My player has the following elements:

Above the story: Tile and Tabs / Left of the story: logo, navigation menu, transcript, search bar / Below the story: seekbar, volume, replay, play/pause.

I have to use the Fixed Player because Rescalable makes the logo and text blurry and has kerning issues. So to find the right story size, my rationale was to look for a course size that would not create vertical scrolls even when viewed on the 14" laptop. 

My courses will include, among other things, screen recordings. The optimal size for the product that I am recording is 1024 x 640, however the product is responsive. I can't use that as my story size as this would create too big of a scroll on my 14" devices. 

So I settled with 980 x 540 as it seems to be the best aspect ratio for 540, height which does not create scrolls.

Does this seems like a good choice? How do you make sure that you have the optimal size for your course? 

Many, many thanks!

Sophie