Does a husband and wife's Patronus always match? (example: stag/doe or lion/lioness)

Is a Patronus always 'life-sized' and if so, is a larger animal Patronus harder to conjure?
My guess for this question is yes they are life-sized and no its not harder. But i'm not sure.

Could a witch/wizard's Patronus take the form of an animal from a region other than where the witch/wizard lives? (example: A witch from Europe -- her Patronus takes the form of a panda bear or a bald eagle)