Great project! You are probably already familiar with the following projects:
It might be worth brainstorming with them, each project is different but you might all have converging ideas about why to build small humanoid creatures and share useful tips and advice.
We recommend using onshape for your design, it is an online cloud CAD that we use a lot for other creatures. They also have very good tutorials if you want to learn. But I am sure you can find other members interested in an upgraded Darwin creature!