Welcome to you from me in Bristol uk.
I have two official mats which are ok but personally I dont like the lines on them.
So I also use a vinyl mat which started life as a table cover as well as a professional gamers mat from Tiny Wars here in uk.
Have fun, I have found the game is fast and fun, especially when you use the advanced rules, the problem seems to be getting people to play, once they do however most say they enjoy it.