Tell me please about your sound habit, englishmen

Hello everyone.
Could you please tell me and give an advice, how should I make voices for my characters. Im speaking about such things as "Accent", "speech style" and "catch phrases". Because I live not in the english speaking country, for me its very hard to find a person, who speaks english like true American or Britain person, and very hard to make him interest to become a voice of my project.
Tell me please, does it will be too bad, if my characters will speak english with accents, or where I can find a cheap english voices for my characters. Also where I can find some sort of "catch phrases list", because I want to make my characters more emotional and understandable for player.
Thanks you.