I get my mannequins from Webster Displays in Michigan at:

http://www.websterdisplays.com/

The Infantry tunic you have posted above is an officer (Leutnant of Infantry) and therefore doesn't have the NCO tress. There are plenty of these tunics out there and no need to buy one that you have to restore. Insignia is getting difficult to find and acquire... not only do you need ORIGINAL insignia, you need to match up the waffenfarben (branch, in this case Infantry), as well as the wear of the tunic. You cannot take a battle worn tunic and add mint, unissued insignia to it; stands out like a sore thumb.

Take your time. Get your book and read up on it first. There is no hurry. And when you find something, post it, including detailed shots, so that we can guide you.

Bill