One thing that bugs me in the shipyard window is how difficult is to go through the long list of ships. To make it more readable and user-friendly I suggest sorting buttons and tabs are introduced. These are already implemented in the designer and could easily be ported to the shipyard.
I suggest starting with at least the basics: sort the list by Hull Size, Weapon Type, Defence Type.
Then once the ships are sorted by that, you can apply secondary sorting, by cost,size etc. It already exists in the designer in some form, we just need it in the shipyard window so we can find the correct ship fast!
Here's a rough and ready mock-up of what I'm talking about.
You can see the long list of ships to what it could look like after sorting.
Hopefully other people will support this and Stardock could consider it!