We had two terrible sleepers. We started with 2 cribs in one room. Eventually, we had to move the cribs into seperate rooms or they'd wake eachother up. Then, 1 of the twins was an awful sleeper. At almost age 3, he was getting up 3-5 times per night. We (my wife and I) hadn't gotten a complete night of sleep since the boys were born.
We finally decided to move them into the same room again at age 3 with Twin sized beds (with railings) and now sleep is awesome. Tehy both sleep through the night, but they do fool around when we put them to bed.
So, in short, two cribs for sure, but it will depend on how your kids react.