A hardcover (translated by yours truly) was released in 2010 by Delcourt. It contains : Issue 0 + The Original Mini with all the extra material (I think we used the "The Dragon" reprint as a basis) - The Dragon: Blood & Guts #1-3 and issues 1&2 of the regular series.https://www.amazon.fr/Savage-Dragon-Bap ... 756018759/
(Price has gone up from 27 euros to 40 because it's now out of print. Sadly, I don't have comp copies that I can part with)
Before that, in 1996-1997, Semic had published the original mini as a trade (with no extras), and issues 1 to 8 as singles containing two US issue per book. That makes four French issues, but if you get the Delcourt Hardcover, you can dispense with Semic's trade and first issue.
You could start by doing searches on http://www.ebay.fr
with words like "Savage Dragon" + "Semic" or "Savage Dragon" + "Delcourt", and see what pops up.
Here's a list of what the French books contain. It might be helpful:
The Delcourt hardcover:http://www.comicsvf.com/fs/18918.php
The Semic trade (from their "Collection Image" series):http://www.comicsvf.com/fs/8694.php#613
The Semic short-lived series:http://www.comicsvf.com/fs/8735.php#1279