EHobbyAsia carries both Flecktarn and Tropentarn sets.
Its not authentic, but good luck finding stuff that fits thats used and authentic from the actual soldiers. They have weird sizing standards.
http://cgi.ebay.com/German-Army-Fleckta ... m153.l1262He only has small stuff in now, but he gets stuff in from XS-XXL sizes, with a breakdown of the sizing in the description.
EDIT: I lied, he has all the sizes in now, in his store, search "German" and see all of his flecktarn gear.
Anything new on Flecktarn.co.uk is not Bundeswehr mil-spec. The used stuff is, but is hard to size, and is expensive coming from the UK.
http://www.sportsmansguide.com has used flecktarn for cheap, same problem with fitting of course, but its stateside and easy to get a hold of. Search for fleck.