The "problem" is that i dont have that much space at home to paint a lot of works this size and also have the problem where to store them in the progress and after?!

I hear you - but you could do it on a "one at a time" basis... have some digital versions of your work style and show those to the restaurant owners when you approach them perhaps? If they say yes to hosting something at their venue - then you could go and create it, also knowing the necessary dimensions. Once that done and out, you could start the next one.

You work is lovely and I wish you all the best with it's success :)