The easiest way to find shirts that havent been released yet, or posted on here is to search asian wholesale websites, these are normally the best place to find them as they normally have the kits made in their country, sometimes they have seen the kits and create fakes as seen here
www.tradetang.com/for-sale/France-Customiz-Away-White-Soccer-Short-Kit09-10-qy0101-/102037-1616061.html
Another way (this is a bit harder) to find the kits is have a snoop around wharehouses where you know they keep the shirts, Kitbag and JJB are the best. But try not to get caught.
Always bring a camera and snap a picture, plaster your name (or username) over it to be sure you get full credit and then upload it here.