I love having a video monitor. It is so much easier to be able to see them when they are sleeping/napping. Also some type of baby carrier. I like the ktan and we also have 2 snugli carriers.
Definitely two swings and two bouncy chairs, I found it essential to have safe places to set them down in the beginning. They napped in their swings for the first 4-5 months...
Re: Must haves