Mark, I commend you for having the foresight to ask that question before doing anything, but the truth is it would be highly irresponsible to buy meat products abroad for use in Ireland... the potential for introducing disease to Irish livestock being the main reason.
You may think a couple of steaks from South America could hardly do any harm, but if they're not certified for import into the EU, and they're the wrong steaks in the wrong circumstances it could be devestating. Take a look at the source of the F&M outbreak in the UK in 2001.
So far as I am aware, you are allowed to use meat from other EU countries.