The choice
TPS
There are some good guys here on this site but the information is free from people looking to, understandably, capture your business.
Please believe me when I say that the best course of action is to commission a truly independent chap to construct you a proper survey and business plan. I do not do it any more myself but can put you in touch with some who do. The value of independent advice from some one who is not chasing your business is significant.
PM me if you would like some guidance.
Regards
MM