Do not use fore/aft positioning to adjust the cockpit length. I usually first set my saddle height to 109% of my true inseam length (not pant inseam). This measurement will equal the distance from pedal axle to the top of the saddle, +/- a few centimeters. Then set the saddle's fore/aft so that a plumb line from your tibial tuberosity (just below your kneecap) crosses the pedal axle when the pedals are horizontal. Stem length/angle/height can be hugely variable and depends on your flexibility and desired position.

All of that is just a start - it will take time to fine tune.