Thera are a lot of 3D programs you can use. In case of sketchup I dont really like how it looks visually, bot for ie low cost architect work, its great. Blender is a good option but gets on its limits quite quickly. I would advise a payed 3D program like Maya or 3DS max, for like developing a case Autodesk inventor is the best, since you can put alot of dimensions and stuff in it. For the most of the time you can get free trials...