Most people intend on going with glass optics and use the folding Magpul rear as a BUIS. Nothing at all wrong wth that - I have an optic-equipped AR with a Troy folder.
But there are other options. If you really take to the aperture sights, you can leave your Magpul on as your rear sight, zero to 50yd (and 200m), forget about it and you'll be +/- 2" out to 250 yards.
But the rifle I like shooting the most has the adjustable carry handle sight. You can buy the A3 detachable handles which will fit the Sports - you just have to be careful to get a good one with mil-spec measurements. Leapers has a shortened version without the full-length handle taking up your rail: MNT-950RS02-B
What's cool about this type of rear sight is the instantly adjustable marked elevation drum that you can set for varying distances. There's a reversible modification that you can do to the drum that allows you to dial down 4 clicks below the 6/3 marking. When zero'd at -4 clicks for 50 yd (200m), the 300-600m markings on the drum will still match to those distances. Theoretically.
There are some bad handle sights out there. If you decide to go that route, I can show you the differences between a cheap sight that may not match the F front and a quality assembly that was made to military specifications designed to pair with the F-marked front sight. Pricewise, mil-spec handles normally go for $90-100. The Leapers UTG "half-sight" MNT-950RS02-B is $30 and is supposed to be the correct height and nice quality.
But don't buy a handle unless you know what to look for.