Not sure if you need a pro, but key dimensions to consider are the length of pull (your face should be about 1 1/2 inches from your thumb on the pistol grip when properly shouldered/cheeked for instance), comb height (to obtain your desired point of impact, reach from pistol grip to trigger should be such that that you comfortably place your finger on the trigger, and cast-on or cast-off (which determines your face/eye position left and right on the buttstock to ensure you are properly looking down the ribd. I believe the BT99 Micro is really designed for the youngster, with a very short length of pull for instance. Whether this is really correct for you can only be determined by you, your size, body shape, neck length, etc. If you have some experienced shooters at your club, you might ask for advice from them, having them observe how you shoulder/hold the gun, etc. You might ask if you could try other guns also to see if any of them have a better fit for you. That would give you some idea of what you need.
Jim R