Does anyone know who makes the NVRAM cards used by NetApp (for F630 and earlier)?
we do. custom boards.
No, I'm not looking to put this into one of my NetApps, but I am looking for a PCI card with some sort of non-volatile RAM that I can purchase. Ideally, some sort of battery-backed RAM -- not flash.
I don't know of anyone who has just a battery backed RAM card but the folks who do hardware RAID usually have some form of NVRAM card to go with it. Try folks like AMI (www.ami.com). There are people who do silicon to help you do battery backed memory but I don't know of them selling PCI cards. For silicon try the folks like Dallas Semi or Linear Tech or Maxim.
Depending on your platform, you could try Cardbus or PCMCIA but it doesn't sound like that's what you have in mind.