Hello There,
I have gone through your requirement & for that, I proposed you to go with the company. Why? Becuase you are with them on a legal contract so they can't leave in the middle of work. Also, you can get the perfect developers in the same rate which you give to the freelancer.
We are a pioneer Website and Mobile application development company. We have a staff of 60+ people including designer, developer, project manager, quality assurance and BA team.
If you wish then I will provide you NDA and I am ready to start with a small milestone or POC (Proof of Concept)to gain your trust on my capabilities to handle this task.
Cheers,
Mahil J