Great game.
If you are looking for a builder race, both Klackons and Meklar are good choices. You'll get to pick tech choices with Meklar, the game will pick the techs for you with Klackon. The Klackon can apply more of their industrial capacity, but need more people farming, so it's a toss-up between the two in production capability. The Gnolam will have to rely more upon buying things, since their production isn't quite as good, but they got the money to do this if you have friendly neighbors.