71 Rear Disc Options

[DjS71]

Looking to get away from the drums in the rear, and want to know my options, make sure I covered all of the bases.

Option 1: Kit from Blackbird's $585 seems like a good deal w/ebrakes

Option 2: Glock's bracket conversion using camaro/impala parts (save a little bit of scratch)

Option 3: I'm not aware of any direct replacements, nor if you could order them from the factory, but is there a common swap 5x5 disc-rear? couldn't find much info on search.

Option 4: Caddy parts ( I admittedly didn't look to hard into this one, so I don't know the costs involved)

What are your thoughts boys? (and the occasional super-cool ladies)