If you made the model really large--say, 30 feet long with architectural model detail--it would put the Cygnus from The Black Hole to shame. That wide stance means you can put a big camera between the nacelles and fly along the top of it towards a city-ship saucer rising in the distance--that was what Ralph wanted--were I to put myself in his shoes.
That is the only way to do that design effectively--coming off as all but being miles long.
I can just hear Holst's The Planets playing as a camera zooms in on this monster...
That's funny, I just made a post on trekmovie about how Mike Minor used Kaplau's MUTINY ON THE BOUNTY music to embellish HIS storyboard of the Enterprise leaving dock in Phase 2 (tracking back with the ship as it ascends, so you see Earth and moon and sun dropping and receding.)
Your notion for that kind of shot is really borne out by the paintscraper flyovers of RED OCTOBER, which are genuinely spectacular. They had to build a special rig with mirror to get lens to seem so close to hull, but with a larger model that wouldn't be as necessary (or they could have used the periscope/snorkel system used occasionally to great effect in TMP (nacelle view as ship leaves dock, SO cool!)
Given that you had so much action in TITANS with the saucer detached, you'd be wise to build one giant model that separated, otherwise you'd have to build additional scaledup models besides the hero one.