Door latches

I am finally getting around to installing door handles (one of the last projects I have). I already have the old handles in from in the house – the porcelain types with the square bolt. What I need are new latches to go inside the door. Can anyone please recommend a brand of good quality ideally reasonably priced latches? Also, if you have any suggestions where I can get them (ideally locally) that would be great too.

Thanks.