I actually just bought one and it arrived today--it's "the body silk seamless nursing bra" by bravado. I tried it on and it's nice--you can adjust everything and it meant to grow with you and be expandable as you need it to be. I've only had it on for a few hours but it gives good support. There's also removable pads that are meant to give you more nip coverage and support a nursing pad later. So far I'm happy with it! I think it was around $40 on amazon and came in a bunch of colors.
I think it depends on the size of your boobs whether you'll prefer tanks or bras. I'm normally a B/C cup, and went up to a D. I lived in nursing tanks, especially the first 6-8 months, but I've heard that larger boobs don't get the support they need in tanks. I have mostly Target nursing tanks, and they held up well. I have two Bravado tanks as well, but I never found a nursing bra I liked that much. I eventually used regular bras with a front closure. One piece of advice is to start with tanks for the first few weeks before buying sized bras until your nursing boobs have settled down a little. It's hard to know where you'll end up both cup and band wise.
I leaked a ton, so I did wear sleep bras, mostly for a place to keep a pad in. I stopped once the nighttime leaking calmed down though. I also went for the Target brand with those.
I sleep in a nursing tank by itself, and have been wearing them as my bra underneath sweaters. I am usually a 34C and I would say I am a 36D now. So I might want more support if I was bigger, but the shelf bra in the tanks works for me. I bought a two pack of bras and two two packs of tanks from them as well as a few from target and gap.