We are looking to set up a limited liability company.
Limited liability companies are difficult to operate in Poland, so are you sure this is the path you want to go down?
No minimum percentages and so on, although 5000PLN minimum starting capital is required.
do I go to Poland on a tourist visa and apply for a residence permit prior to the 3 months period expiring or
You deal with everything here on the tourist visa.
Do you also happen to know of immigration agent to assist in this matter?
Oh, and yes, I do. I know someone that can handle everything for you remotely. I've sent you a PM with his contact details.