Hi there,
I'm a mechanical engineer with over 15 years experience in designing, modeling, prototyping and effective manufacturing of different products, ranging from consumer goods to alternative energy systems.
Because my experience into the industrial field with stirers, agitators and vibrators of any kind, I'm confident I could make your model with no problem.
A short observation btw the videos provided(links): for the first one, that shaker is kinda limited, because not all nail polish recipients are the same (in diameter or shape) - I tell you for sure, so the holding system is inadequared.
You required at least 2-3 versions and first model to have 1 station and the second 6 stations.
What I'll propose to you: a combined mechanism which to provide both movements - oscitating-linear movement and also shaking with the same motor(I already know how to do that). In terms of exterior shape (this will be the first step) I'll design 2-3 rough models, and after discussions on these, I'll continue with the chosen one (or combinations of elements from all).
For the second model - with 6 stations, that will be separate, even here on Freelancer or outside.
What I'll deliver: 3D model in different CAD formats (iges, stl - for 3D printing, step, etc). 3D pdf so you'll be able to open/view the model into Acrobat Readrer, execution drawings and BoM (bill of materials)