What is a good storage array for a home server?

[Mystical Kimchi]

I have an HP DL380 G7 server at home. It's the model that holds up to 8 2.5" drives. I'd rather use 3.5" drives since 3.5" drives are less expensive and come in larger capacities. So I'd like to find a decent storage array that I can attach to my server and make use of 3.5" drives. But frankly this is something I don't know much about. Can anyone recommend what I should look for in a general sense (such as features or even things to avoid)? And can anyone suggest specific models that would be good? I've got a 72U server rack with plenty of space, so size isn't a major concern. Low power draw would definitely be a plus. But primarily I'm looking for something compatible with my hardware and that I can pick up at a reasonable price off eBay or some other used hardware seller. I'm running FreeBSD and using ZFS in a mirrored configuration if that makes a difference.