There is no Spanish version for Snitz 3.4. There is one for Snitz v4.0Beta3Patch5. AFAIK, currently has no known security problems, so you can use it for your forum. I use it for mine.
Snitz 4.0Beta4, functionally equivalent to Snitz 3.4.0x, should be out in a few days. You can upgrade when it comes out.