I will disagree with the statement that you must keep a pair. Rabbits are not necessarily social, and they fight. I realize that sometimes pairs will bond, but I think that's more the exception than the norm. And for fixed animals.
What is your purpose for your new bun? Pet, breeder, show, meat? Your other post mentioned keeping outside with chooks. If so, you'd want to pick the right breed for your climate. A feed store might have good recommendation, but it doesn't sound like yours knew much, so I wouldn't buy there. Junebug gave a couple nice links. My daughter has a pet dwarf hotot buck that is super sweet. But he's an indoor bun. Mini rex are super soft, but you have to know how to care for their fur and prevent sore hocks. Btw--bucks are generally nicer than does for pets.
Ditto on the water bottle vs a dish. And get a bigger one than you think--they drink a lot. Depending on your cage, I like j-feeders for my wire cages. The dwarf hotot has a nifty little combo feed/hay feeder that I like.