I purchased several ships from multiple races.   In my last game, i played as the Drath and quickly built up my military by asking for a few ships every time I traded some tech from other races.

I also bought all the scouts and space miners that I could, converting them to constructors that I used to build up my starbases.  It was much cheaper than building a constructor from scratch.   In this game I didn't build many ships, I mainly did ship upgrades of the many ships I purchased from other races.

I only rushed-purchased a few transports and a couple of fighters near the end but by then my economy was doing well.

Anyhow, when I upgraded Fighters of one type (could have been Yor or Thalan, the name was an alpha-numerical sequence)  when I selected "upgrade all ships of this type"  the ships would all keep their names.