Okay well that's a lot, thank you very much it is a great help, I actually didn't even know that lego discontinued the small and medium angular motor, hopefully I think I have already some.
I'm going to need some reflexion time to think wich way I'm going to do this ( and also because I'm going to ask my ingenieury classmate and teacher about this). Actually I can't really decide I think, since I don't have the set right now ( will have it the 29 normally), but I have heard to about the suspension problem (not sure if this is English correct ).
Anyway I talk to much. You have been of an incredible help, thank you really really much o(^o^)o.
I'm doing the arm at the end. I really really want to make it more "accurate ". And also because I think I can take it as my final project for my engineering class (which if the teacher is OK, would be freaking amazing). But thanks for the ideas.