[@Alfhedil] I mostly meant that setting a character in that time would be difficult since it was so far in the past.  And Mandalorians reforge their armor every generation.  Every existing clan and new clan also has their own armor (example: The subtle differences between Clan Wren and Clan Kryze aka the Nite Owls).  So the old republic armor wouldn't still be relevant or even depicted in the new generation of Mandos.  

However, I made that statement after making a reading mistake.  But those are the two things I was trying to say.  Setting the character a thousand years before all other characters would make it difficult for any of the characters to interact, and Mando armor would be many, many generations past that era.

As far as the species and families from that era, while they would have evolved quite a bit, I'm sure they would still be around to some degree.