Magnification: ACOG TA31F 4x
EOTech: I own an EOTech 511, but I wouldn't buy it again if I could go back in time. If you do get an EOTech, make sure it's a model that uses CR123 batteries. Beware of the Chinese fakes out there and buy from a reputable optics dealer, like Optics Planet. Also, the EOTech magnifier is just goofy: With the magnifier and EOTech sight together, they weigh more and cost more than an ACOG and take up all the top rail space.
Inexpensive magnified: Leupold Mark AR 1.5-4x20mm
Less expensive red dot: C-More RTS, Zeiss Z-Point
Inexpensive red dot: C-More Railway
You could also mount a cheapie red dot on top of an ACOG, or on the rail using a 45 degree canted mount.
Save money by not wasting it on backup iron sights that you'll never use, need, or want.
Agree on almost all of that, but BUIS on my red-dotted ARs is a must. I routinely practice stripping the optic off in a failure (ARMS QD mount) and flipping up the backup sights.
If you still have the eyes, practicing with backup iron sights is essential.