It seems that Arpa is right. The armenian-basque relation as remanents of a pre-indoeuropean languages seems to be a very weak theory that almost nobody accepts. But it's curious.
Vahan Sarkisian, an armenian linguist has write a 600 words list with similar words between basque and armenian: toponimics as Araxes or Deba and ancient words as "ardo" in basque ("wine") and "ort" in armenian (also means "wine"?). If I found the list, I'll post it to you.
Despite of this, basque linguists are agree with Arpa's opinion that they are only coincidences. I supose that you know this article: a evolutinary-like tree with all indoeuropean lenguages. The armenian seems to be a very ancient branch, but it's INTO the tree. The basque is OUT, it's pre-indoeuropean. In fact, they don't mention it in the article.
http://www.psych.auckland.ac.nz/psych/rese...tkinson2003.pdf
So, I must continue looking for an origin for the basque word of "sirats". I'll try with the old french languages. If I find a forum with people that helps me as well as you have done, I think that in a week I'll became an expert linguist.
Thank you very much for everything. If some day you want some information about basque language or our country, write me without fear.