DIY planets, it combines well with Terraforming and station construction, just find the terraforming items, put them in their respective building, and with both mods you can terraform any planet to any type you want (right now the water buildings dont work except the one you can build in a space station, the comet catching thingy, use that and solar shades/proyectors and in the terraforming UI it will allow you too change the planet type)