Not really needed for a new born baby, but once DS became mobile, I really wish I had a video monitor. We had no use for the traditional, sound based monitor, as we could hear him just fine. BUT around 10 months he started sleeping most of the night in his crib, and would have been helpful to know if when he was making sounds, if he was making them in his sleep or was truly awake, and going in to look in on him would wake him up. (inevitably, we do go in, because we can't see him, and he is awake by that point and has to be cuddled or nursed back to sleep. Not a bad thing, but it would have been better all around if he didn't have interrupted sleep)
As for cloth diapers, some of it will be trial and error, I think prefolds/covers (or fitteds/covers) will work on any baby, but if you want to do pockets or all in ones (these are best for daycare situations) it may take going through a few styles or brands to figure out what works best on your babe.
We didn't have a baby bathtub, we had a mesh sling seat and it is great! I even used it to have DS in the shower with me when he was a little older. (3 months or so)
A baby scale - we don't vax, so we don't see the ped as regularly as some, and I love being able to keep track of DS's weight on my own to track his growth. Again, not really a "need" per se, but DS is a lean man and it went and goes a long way to put my mind at ease.
As for clothes, everyone says, don't buy newborn stuff, they grow out of it so fast, etc. DS was not quite 7 lbs at birth, and we NEEDED newborn stuff, and had very few items. We bought and borrowed after he was born to catch up. I love sleep gowns and sleep sacs. anything with zippers, really, I don't like lots of snaps. When babies are little it isn't so bad, but as they get bigger and squirmy, it takes longer and gets more difficult to do them.
Muslin blankets (like Aiden and Anais) - great for swaddling, covering when nursing (if you want to), and as a light cover in the summer. They are huge, and will go a long way.
Do shop consignment and yardsales.
We have the Combi Cocorro convertible, and I love it as a carseat, so cushy, doesn't take up a lot of space, and fit DS well from birth, and still does at nearly 15 months. We also have a babytrend infant seat for the other car, and I have to admit is handy for restaurants and grocery stores. I really liked having both, now when this baby is born, all I need to buy is an extra base for the infant seat, since we now have convertibles in both cars.
Things I wish I hadn't bought: swing - took up too much space and DS didn/t use it much. Crib bedding - all you really need are sheets - bottle warmer (we warmed a pyrex measuring cup of water in the microwave and stuck our glass bottles in that to warm up, takes about the same amount of time) - so many disposable diapers - we used them for the first 7 months, and DS grew out of our massive stash - (don't prebuy too many in one size)