You're absolutely right, Ulrich- plate front greaves, or schynbalds if you prefer, are perfectly acceptable for 13thC onwards (1200AD on). You'll need them to your measurements, though- if you don't tell him, he'll build it according to
his measurements and he's a bit taller and heavier than you are.
Do you have a reference or link for the statement
They DID have early coat of plates by 1250 AD but most of them were worn UNDER the hauberk which leads them to be hidden
- I ask because I'd love to read about that. That is not to say I disbelieve you, just that I have never heard that in the research tomes I've bothered to crack so it is of interest to say the least. It would also seem to be counterproductive, as maille's strength is that it conforms to the body and not the other way around; having something as hard and unyielding as steel beneath it would (and this is just my humble opinion) render at least some of maille's protective properties moot.
I am sure one of my more learned brethren will correct me if I'm wrong.