I would suggest to look at fellow rescue sites and ask if you can use their adoption sheets. Also ask the rescue org. what the correct answers are to their questions so that its like an answer key. You want to be sure that they are going to the best possible home. The worst is to rehome a pet chin, to then see it rehomed again...something thats best to avoid for stress on the animal.
For the attachment problem, you said yourself, you guys are not in the position to have more animals, so just go in it full knowing that they will be offered a better home than you can offer at this time. They will be able to receive full attention that they need, and god forbid one gets ill in your care, medical attention is very costly, and having more chins increases the chances of having to take one to the vet. But i really applaud you for thinking realistic because many owners will keep them because they're cute, and then they'll run into a brick wall when that vet bill rolls around. KUDOS!