SMAC let you do this. The components all had costs, and the reactor upgrades increased their power, and IIRC reduced the costs. So as you advanced you picked an

SMAC let you do this. The components all had costs, and the reactor upgrades increased their power, and IIRC reduced the costs. So as you advanced you picked and chose what frames, reactors, components, armor you want. It let you do things like Colony pods with orbital insertion, or submarine probe teams. Very fun.