PS Vita games and international restrictions

Apologies if this has been brought up prior as I couldn't find any answer to it, but I'm currently looking to buy a PS Vita, however notice that the selection of games are limited, especially in the sports department. Specially, I had my eye on a couple of more american-aimed titles such as the MLB baseball game.

Being a limited user of most gaming devices (and thus very limited knowledge other than to turn it on a play!), would anyone be able to advise if:

A) there are any international restrictions on games and the Vita itself (ie game purchased in the states but being played on a Vita bought in Ireland or visa versa, or alternatively can they be downloaded?).

if not, is there an online or retail store who would sell a wider range of titles to chose from?

Would really like to purchase one to use on a couple of long haul trips planned, but the limitation of games available that interest me are holding me back, as well as where I can get them.

Thanks.