All of the dogs we fostered were ill and contagious to other dogs, but not dangerously so (Kennel cough, mostly). The Humane Society had a program where one could take the dogs home and care for them until they got better, then bring them back to be adopted. We fostered 9 - my roomates kept the first one, and I kept the next-to-last one.

It was more work than having a dog, because essentially we had a succession of 3-4 week periods of having a puppy in the house. On the bright side, the Humane Society always got back a dog that was better behaved than the one we picked up. I wouldn't do it again with my work schedule, though, and I have more time available than you seem to have. You can wait a couple of years to get a dog - it would be better for both of you.