Colt 6720 Lightweight AR15 is probably the best option. It is lighter than most AR15s and reliable. Its also cheap, with some as low as $850 new.
You first have to decide on which "semi-automatic" platform you'll be most comfortable with, ... but since you indicated having some past familiarity with an AR and its manual-of-arms, the 16" Colt 6720 is a solid choice.
As HGM22 said, it's light-weight and uber-reliable, and there are any number of simple and affordable mounting options for a flashlight.
Plus, for right now at least, and despite recent incidents of media-driven, over-politicized gun-hysteria, we're still in the midst of a general market glut that
favors the buyer in all-things-AR - rifles, hi-cap mags, and 5.56/.223 ammo.
How long that will last is anybody's guess, but that means there's no reason
not to buy a carbine or rifle from a
top tier *name* AR maker, like Colt, DD, LMT, et. al., because their price-point is about as low as it will ever be, and their name will retain significant resale value down the road.
Like HGM22, I've seen various Colt ARs collecting dust on the LGS shelves with price tags on them between $890-$950, ... and you might do better if you can find one that's was someone's impulse buy 2-years ago and is only *lightly-used*.
$1500 can cover a lot of ground right now, so after grabbing a 6720 and some type of decent RDS, I'd stock up on a case or two of quality 5.56mm ammo, and add more as funds permit.
Wait until later to add all the blingy, cool-guy accessories - if you just can't resist (and some dudes can't) - again, as your income permits.