Editing and paraphrasing my email I am sending

Can you please edit and paraphrase my email if there is any mistakes or poor structure…

” Dear Sara,

We want to check if our assumptions are right, based on your experience, do you think it is reasonable to have the following numbers for speedlab cub:-

1. 21 costumers per day and each costumer prints 3 photos of 4’*6″

2. 7 costumers per day and each costumer prints 2 photos of 8”*12”

To reach break even point in the first year I had to go with the above assumptions if they are not reasonable please advise and I can change the pricing a little bit.

Regarding the curtain we wants it to be just around the screen and has only the screen length. if you can make it as small as possible to be convenient and not to cover the machine.

The main purpose of the curtain is to cover what the costumer is printing to give them privacy. for example, if two costumers are standing on the line to use the machine, the one who is waiting should not see what the costumer is printing but he should see that there is a costumer using the machine.

I will inform you about the visit to France once we get our visa done”