Two players, ten starting planets.
Make a map with tewnty starting positions grouped on either side of the quadrant in clusters of ten. They don't have to be all ten in the same system, just close to each other. Add 20 spherworlds and have those be your starting positions. One group of ten starting positions should be all the odd player numbers, the other group of starting positions will be all the even player numebrs.
Then create the first turn, using player one's empire file ten times and player 2's empire file ten times, even and odd.
If you are doing this on PBW the first couple turns will have to be processed offline. Each player will play all ten empires long enough to make contact with all ten of their empries, then surender the nine additioanl empires to their first empire.
From that point on the game can be played as any other 2 player PBW game, but each player will have 100 homeworlds, ten of which will be spherewolrds.
It doesn't have to be a high tech game, but with that many planets research is merely a formality anyway.
Geoschmo