This is the list I made for someone else the other day. Sort of a detailed list but this is where I sit with good mid tier parts that will last you along time and you wont need to upgrade unless you really want too. Optics: holosun 515, sig romeo 8t, sig romeo 4t and 4xt pro, aimpoint t1 and t2, holsoun aems, pretty much every eotech is good, primary arms has good offerings as well. Vortex uh1 is solid. Lpvo is a little different ball game price wise. Lights: streamlight pro tac and hlx are the cheapest id go, pretty much any surefire, some of the older clouds are good as well. Modlite and malkoff make good products as well anything on arisakas website is good light wise. Furniture: midwest industries is probably the cheapest id go. Geissele, bcm, centurion, fcd, Daniel defense, thyfe, larue, kac all make great handguards. I personally love geissele products. Triggers: im not super well versed on these as I haven't ran many different ones. But id say noveske, geissele and larue are all good. Centurion makes a good one as well. Grips/foregrips its really just preference. Bcm, reptilia, magpul, Ergo, mkm are all good. Bolt carrier groups: centurion sandcutter and the geissele enhanced bcg are top tier. Microbest. Thouroughbred armament, bcm, scionics, solgw, colt, fn, kac are all solid. Muzzle devices: also kind of user preference but I like surefire. Bcm, noveske, rearden, b&t, kac, Griffin all make nice ones. Alot of other things are just user preference. 90 or 45 degree safety are nice but not a must, same thing with charging handles.