First, welcome to the forum, and to the wonderful world of Krags.  I think you will find that they are among the most accurate and smoothest operating rifles ever made. 

Your rifle looks to be a very nice sporter, and well done too.  Although it's barrel has been cutdown, it should still perform well as a good shooter.  Rather than replace the stock, you might want to look for an original military Krag to compliment your sporter.  They can be found for decent prices on sites like the CMP, Gunbroker, etc.   I don't know all about the laws in France, and whether they can be imported, but it's an option.

If you're set on replacing your stock with a military stock, they can also be found on ebay, and other sites.  Rear sights and hand guards can be found too.

Good luck with what ever you decide to do, and keep us informed!

Paul