I've not made any decisions on wonders yet, some of what you see from KSR mars trilogy will not be in the first scenario. For instance it will be too early for the space elevator.
I'm thinking of themed wonders;
Teraform wonders
Mohole (big hole in the ground that lets out geothermal heat).
Black dust on the polar caps.
Orbital mirrors (focused on the polar caps).
Engineered plant life (widely distributed).
Chemical coctail factories (let out green house gasses).
etc...
Each would be called a different initiative number, such as Initiative #1 moholes, and would perhaps be small wonders. Each would require the previous one in the city, and would eventualy alow the building of a great wonder that would allow the UN victory.
Military wonders
Equatorial launch silos
Phobos military base
Demios military base
Surface photography
Urainium reprocessing.
etc...
Again they would be small wonders that lead to a great wonder that allows nuclear missiles to be built (or spawns ICBMs)
Medical wonders
Human genome project.
Cybernetic replacements (would spawn martian veterans).
Genetic modifications
Memory copy technique
Replacement organs
etc...
This would be quite a short theme and would give the one who completeed it first access to the longevity treatment or ectogene cloning that would give two citizens each time the city grows and would allow the city to grow to metropolis size ahead of time.
Perhaps the first few wonders would be small wonders alowing a race between civs, but the later ones would be great wonders meaning that if you wanted to prevent someone winning the teraforming race you would have to destroy the cities that house thier required great wonders.
I've had a go at adding some individual details to the leaderheads, I may make them static to start with just so they are available for early testing;