I'm looking for a NAS solution

These days I've been looking for a NAS (Networked attached storage) solution. I have lots of photos and videos (especially after the wedding!) and I don't want to just keep them on my desktop. I would like a central place to keep all those files. Right now, that "place" is my desktop, but it makes sharing difficult. However, there are many NAS solutions out there and I don't know which one I want.

Here are my thoughts/questions:

I don't want more than 2 disks. More disks just means more failures, and I don't need the performance of more spindles. I don't have gigabit ethernet and most devices are over wireless ethernet, so my network is the bottleneck.

I want it to be able to share with Windows, Mac, and linux, since I have all 3. I think that means CIFS, AFP, and NFS, but I'm not sure.

I want more reliability. Can I get that from RAID-1 alone, or will I need backups as well?

Can NAS RAID-1 boxes use drives from different manufacturers?

For a RAID-1 setup, if 1 drive fails, can it still serve off the other drive?

If I remove a drive from a RAID-1 setup, is it readable by other computers, or is there some special RAID formatting on the drives?

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I don't know all the answers yet, but from what I can tell, I don't think a 2 disk NAS with RAID-1 will do what I want. I think the single point of data loss is in the raid controller. If this is true, I think I will just go with a single drive NAS which does automatic backups to another external drive, which will give me a poor man's RAID-1, no RAID controller to depend on, and the sharing capabilities of a NAS.

But if there is a great 2 disk RAID-1 NAS, then let me know!