I am sort of a person who likes unity in my quilts(and I am referring to the border) that is just me, but I think whatever you decide for the outer border, I would pick something that is already in the main quilt, be in bear paws or flying geese and do that on all four sides;I think to do two sides one way and then two the other, would make the entire quilt way too busy looking - think of it as a picture frame and since the quilt is a "sampler" already, and samplers are usually busy looking, the border will sort of give it a calming effect if it is the same in design and tie it in
all together.
what about replacing the hearts(I know why they are there, I love them also)
but since it is for a son, why not applique a maple leaf on a plain block instead or put in a pieced maple leaf block - a bit more for a guy? Just some thoughts - or do you have a "house" pattern you could use to to replace the hearts??