Best HDD for specific purpose

Well i'm concerned with my data longevity, and ive been looking for cheap solutions...

CDs get damaged easily, and have lengthy burn times.

NAS's are quite expensive

RAID has problems, needing RAID cards, etc.

So I figured I just would do this...

Find a large (2TB preferably) HDD that supports hot-swap, is stable and reliable. Basically I want to move some of my lesser used data, lessening the loss if my primary HDD were ever to crash. In essence, id use it as a large flash drive. When I need to access the files, id just pop it in. What do you think would suit me here?

A WD Red? It doesn't need to be hardened to constant use, so idk about reds, or other NAS solutions. What of enterprise drives? I know servers are hot swapped often, perhaps their drives would suit me?

I would make RAID1 on 2 cheaper drives with longer warranty. No matter what RAID controller ( can be even software windows option ). It doesn't have to be fast as it's just an copy.
Best SATA series for me are WD RE4 but they're not cheap. The same REDs are not cheap. You can probably find some standard Blue/Green drives and make 2 copies just in case what will cost you nearly the same as one enterprise grade drive ( which can fail too ).
All SATA drives support hot swap. Point is if board/controller supports it. You can always connect it via USB and then it's no problem with hot swap.