Appreciate all the info Frankie. The rough opening is 81HX96W, a little higher than I recalled. The frame is cinder block sides, 8" block with slabs for top and bottom. I could actually gain a few inches at the bottom if needed, the previous owner of the house poured a ramp from the back brick deck to slab in the area I am looking to close off. It is about 6 inches tall and about 12 to 14 inches from where it starts to where it meets the slab. This ramp is actually from where the slab meets the cinder blocks outward so it sits inline with the walls if that makes sense.
Hollow metal door frames can be made to fit any opening. There is a frame profile made to fit around 8" block, It's called 8-3/4" Masonry frame.
The 81" height is not a problem if you select a frame that wraps around the wall, instead of just butting the wall. Wrapping the wall is also more secure. You can still use standard 2" face frames, and 6'8" doors.
96" is getting close to the maximum width you can get in standard doors. The widest hollow metal doors available are 45" each. Allowing for a wrapped frame you would still need one 48" wide door, which is called a "four -oh" door (or 4'-0"), and one door 46" wide, called a 3-10 ( 3'10") door. the frame being a 7-10 x 6-8 frame (7'10" x 6'8" wide) The overall (outside) dimensions of this frame would be 98" wide x 82" tall. That would allow you to wrap it around the wall by 1" all the way around.
You could add flush bolts to the inactive door, which would lock one door down when not needed to be opened. The locking bolts would come from inside the top an bottom of the door, and latch to the frame head, and to the threshold.
If I were to outfit this opening, this is what I wold order.
1 each: 8-3/4" x 710-68 Hollow metal frame Knocked down.
1 each: 4068 door, non handed, prepped for 161, deadbolt.
1 each: 310-68 door, non-handed, prepped for ansi strike, deadbolt strike to match active door, flushbolts.
1 each: 2 piece astragal ( w//FB cutouts.
6 each: 4-1/2" x 4 1/2" Hinge (finish to match lockset) NRP ( non-removable pin).
1 each: entry lock set, and dead bolt, keyed alike.
1 each: threshold 6"x 72" x 1/2"
2 each: 48" door sweep
1 each: Weather strip 72" x 80"
Recommend a closer on the active door, and I also recommend that you install the doors so that they open out, instead of in.
An installation like thins would take about a professional install with a helper about 2 hours to install. You can do it yourself with a helper in about 4 to 5 hours.
There is an alternative, and since its a block wall, it will be fairly inexpensive. You clan close the opening down to 76" wide, and have a 6' wide opening, and you can use two 3foot wide steel doors which are available at most home improvement stores.
A 3068 (3'0" x 6'8") 18 gauge door prepared for a lockset and a dead lock and 3 hinges will run about $300.00 avg. you would need two.
The frame would be about $175.00.
Home depot sells locksets and deadlocks, keyed alike ranging from about $45 and up. I would recommend that you stay away from the "Quikset" brand. Spend a few extra dollars and buy Schlage, or Sargent, or equal.
4-102" himges will cost you about $6 or $7 each plus weather strip and threashold...
If you want windows in them, like the pic in the OP, you can order those. The ones in the picture are called "Narrow Lites". they require a 5" x 35" cutout in the door, and give you a 3" x 33 " visible glass, and require 1/4" thick glass. I would recommend 1/4" Laminated glass if you do that. If security is a issue, use 1/4" thick wire glass.
That door set will work with your existing opening. secure the inactive door closed when not needed, and give one one "active" door.