Here is a moder version of such a harness.
http://www.varmouries.com/tran_01.html Here is a webpage that has one guys attempt at a reproduction of the breastplate from the #13 churburg harness (held at the largest private armoury at churburg castle). It is nice because the pictures on the right are pictures of the original museum piece.
http://filebox.vt.edu/users/jselmer/churburg.htm This type of harness has full arms and legs, greaves, sabatons, spaulders and a good helmet. It sometimes refered to as transitional because it uses chain as a large part of the body protection. You can get started with this armour with just the plate pieces and a good gambeson, but to be really safe you will need a good riveted shirt to help protect you from the thrusts that occur in practicing historical armoured combat techniques. the armour is held on by points (sewn down cord that you tie the armour to you with) attached to the arming coat or gambeson. For holding up the legs, I am enamoured by the idea of pourpoint, basically a tight vest that has ties that come down to attach the legs to and that the arming coat goes over.
Also, you could go with the a velvet covered coat of plates, instead of the #13 breast plate such as shown here.
http://www.varmouries.com/tran_10.html This of course gives more solid protection to the belly and down to the hips than chain used with the #13 churburg.
hope this helps.
Brian Hunt.
P.S. I am in the middle of building my own set of 14th century armour. I have the #13 breastplate done, and I am currently finishing up the helm. I have the legs and arms cut out, but nothing shaped yet. Too many other projects that have 1st priority, such as fencing helms for paying customers. <img src="/forum/images/icons/wink.gif" alt="" />
