I got lucky. I only REALLY got attached to one and stratigically placed him with a friend of my dad's who let's me visit whenever I want. I hope to be able to do the same with our upcoming litter. 3 are already placed (1 w/ me, 1 with a family friend who will let me visit and doggy sit, and one with a co-worker/friend) Don't know hwat i'm going to do when I run out of friends and family.
Seriously though, yes, I know it is hard. You just have to bite the bullet and do what you know is best for the dogs.