If I remember rightly, we'd do a rinse cycle with just the nappies, then if we didn't have a big enough nappy load we'd make up the remainder with towels for the main wash, to make sure the machine was about 3/4 full. Pre-weaning poo is pretty inoffensive, you just need to make sure you don't use a 'reduced water' cycle. After weaning when things get more solid you tip the bulk of the poo into the toilet when the nappy comes off. We used fleece liners and the poo kind of peeled off.
Brands is really personal I think. We used a combo of close pop-ins, grovias, little lambs and good old fashioned terries+wraps in the day. My favourites overall were the little lambs bamboo, but they do take the longest to dry. Terries were the most faff but quickest to dry, and the close and grovia sometimes were a bit less good for containment but brilliant for convenience and good drying time.
At night we swore by bamboozles - sadly the company went out of business recently so I'm not sure how available they are now.
I honestly don't remember how many we had, it's amazing what you forget 😅 I'll be digging ours out to get ready in the next couple of weeks so can let you know if someone else hasn't already provided a more useful answer!
I don't remember any issues with using them at night. One thing to mention though as I alluded to above is that a lot of brands won't fit a newborn unless you buy the newborn specific size, and that does get expensive. If you want to cloth from the start it is definitely worth seeing if anywhere can hire you a newborn nappy kit.