From the OP's post I was under the impression that it was the game system that the DM did not want to use: MGT is neither D20 or Hero.
Some other points...
There's no powergaming in MGT? Wait until they get their hands on Battledress and FGMPs.
(my campaign won't have that high of a tech level; speaking of which...)
---- I'm setting up a Traveller campaign in my own universe; I've written up my own version of human's near future. Recently (like started last week

), I've given some thought to a subset of it for a smaller-scaled version: a large colony ship misjumped a far distance (about 200 parsecs) to a local star cluster teaming with stars that are not far apart. Add a few hundred years you have one main world, a few colonized worlds, and some outposts for a "Firefly"-esque set up. To help speed up the colonizing I was thinking of having a nearby alien species (I have 15 mm lizardy-people) just coming out of their own "Long Night"; they had already gone through the area long ago and "terraformed" a lot of worlds (i.e., tossing comets at a few, seeding others). This could leave a few "alien ruins" for exploration purposes. And this sets up a hostile alien species that is quite upset that someone took their "lands".
----- You won't have hundreds of large ships for fleet actions, a la Star Wars, but you might have a few precious capital ships (battlestars

) and some escort type ships. You also have a lot of exploration room. And, when the people realize they need help from Earth to fight the aliens, they send an exploration cruiser (read: Aurora class from TNE) to find and contact Earth (they know the general direction, but nebula, dust clouds, and dark matter block the view). But that's for a second campaign.
----- My main issues at the moment is how long does it take for a 20,000-30,000 Terran flora/fauna/human mostly-seeds/embryos cargo (plus crew) colony ship to set up a civilization with a decent sized population (say, 1 billion humans)? Even with some pre-terraformed worlds, how fast can Terran ecology be set up on a planet? I read that the blasted island remnants left after Krakatoa are now lush with vegetation so it seems that plant life only needs about 100 years to settle in, on Earth anyway.