What do you mean by 'good for upgrading'?

You do know you can upgrade any and all blocks of a ship from a lesser material to a better one(and vice versa), right? Or are you looking for a ship hull you can add your own internalrs to?

Because that's quite hard if it's not filled with framwork blocks, and a lot of parts of a ship are kind of predetermined by it's size and function - you will always have to have a certain amount of mass dampeners, gyros, engines and thrusters to keep a ship moving(who's numbers are determined by the ship's size), and those same require a minimum amount of energy production and storage.

So in a way, the only thing you can change with your ship(buildwise) is the amount shields and armor, and also wether or not you have hangars, torpedoes and it's hyperjump distance. And yet again, adding those also adds aditional energy requirements, and all that add's to the ship's weight, which means you need more thrusters, gyros and engines to keep it mobile.

It's a vicious cycle, that's why it's hard to get a ship that's tanky, nimble and good looking.

If you want to learn how to make 'pretty' ships, first try to get yourself to xanion zone without skipping and worrying about looks, and playing on one of the harder difficulties. This will teach you how to make a ship that's balanced(mobility vs utility vs defense vs offense).

Once you can figure out the ratios, you can start experimenting with different looks - try downloading some builds from workshop you find nice, and look at how they were built.

And don't forget, no matter how much you sculpt a piece of dung, in the end, it's a piece of dung(a.k.a., doesn't matter how it looks if it takes longer to complete a full turn than a clock arm).

And of course, good luck on your endeavors(both with creative efforts and workshop searching).

Watch in my new Collection Ferret Heavy Industries - Ships LINK maybe you will find some nice Stuff there.