Frosty
Hello & Welcome to the Forum!

I am what is referred to as a Toy Train Infidel, so whimsical/fantasy trains are just fine with me!

I could see someone kit bashing or scratch building a Starfleet Class F Shuttle locomotive.  A Type 10 Shuttlecraft has beautiful lines, but would be a challenging build. The Lionel Acela locomotive was my immediate thought for a bash, similar lines to the Type 10 shuttle but it is way too long.
I would consider bashing the shuttle mode that you have found into a locomotive using an 0-4-0 chassis.

I hope you decide to go with a Star Trek themed train.  If you do, take lot's of photo's and make a build log to share with us.

Happy Rails!
Dave