Nice!
Powered Asteroid Mothership for homeworld/colony defense?
The ubiquitous Monitor?
A commercial survey ship?
A high-tech truly Alien vessel? TL 18+?
Sentient bioship? Like Moya of Farscape.
A better ringship than the labship design?
A sleeper ship like the Botany Bay of Star Trek?
A beanstalk space station?
More saucer types?
just to get your creative mind going.
You still should do a pdf to sell.