Personally, I would not buy anything off Ebay.
My first place to shop is Primary Arms.
Midway is midway between midrange price and high price most times, Cheaperthandirt isn't really, Optics Planet is the wal-mart of the internet. Be careful of additional shipping or processing fees on top of shipping price from all three of these. Reviews at those places are mostly worthless.
Shop the actual company that made what you want also, sometimes their prices are lower than elsewhere even the above three.
Brownells is ok, Cabellas is consistent for ammo price and usually well stocked.
Red dot sights with over 3 MOA dots are useless for tactical use, anything over 2 MOA is useless for critical quick engagement precision. Do not skimp on something your life would depend on, do not treat selection casually based upon low price. Stay with the brands well known for tactical use red dots that are classed tactical use and not general or hunters use, stay with companies with proven track records in tactical or combat use RDS. Its true these are generally higher in price but they are made for tactical use with engineering, structure, and components design based upon real world criticality application thats specifically tailored to offer the best chance of reliability and dependability under critical, demanding, and harsh use. For tactical use, for example, a new red dot that costs $60.00 from the "budget menu" is not going to equal a red dot that costs $300.00 from Aim Point or EoTech I don't care how many people tell you otherwise or how many reviews you read because it just ain't so period. Its like the difference between having a dentist do your heart surgery instead of a heart surgeon - both called doctor but both are not equal for their application and one will be more likely to fail you during the most critical time. So unless you plan on possibly flossing the bad guys teeth stay away from the budget menu for tactical use RDS.
For quick tactical use forget the vertical and angled grips (or support hand magazine well grip). These simply set your support hand back too far or at the wrong position for quickly "driving" the weapon between targets, to a target, or for moving targets, suitably. Learn to use the support hand forward "driving" grip instead, and spend the money on something else.
Flashlights, lots to choose from in all sorts of price ranges. Some are ok, but a lot are more "gimmicky" than useful. The tactical flashlight has three basic purposes, illuminate, momentarily blind, and aid aiming on, a target. A few tips; Illuminate in this case does not mean to just put light on a target, it means to put light on the target so that the light actually helps you hit the target because it has a bright "hotspot" that covers an area of the target you can reasonably expect to hit with a quick shot at up to close engage range of 25 meters in dark or near dark conditions, this means a light with about 100 lumen and a light source that does not have gaps and shadows with a "hotspot" yet still casts enough light over a reasonable area of the target to see places for follow up shots if needed. The ideal beam has a bright center "hotspot" for identifying distant threats and acting as an aiming aid yet has a smooth sidespill of light to aid peripheral vision. Do not get a incandescent flashlight. Go with LED lights with a textured or "orange peel" reflector. "orange peel" reflectors are better and allow for a beam that is very smooth with a bright "hotspot". Textured reflectors allows for more distance but the sidespill generally is more cut off rather than dimishing, beam is a little less bright at the center with beam quality more defined but a little less smooth and more abruptly dimished at distance. For close in choose beam quality over light throw distance past 25 meters. Aluminum construction with Hard Anodized Type III, using CR123A lithium cell batteries. Mounting should be parallel to the weapon bore line mounted below (best), mounting above is not ideal due to tendancy to chase the light in the dark while shooting and can chase light off target more quickly and miss, side mounting causes a shadow due to barrel or forend obstruction and decreases side peripheral light which you don't want to lose. Mounting below and parallel to bore line preserves peripheral light more to the sides and below the weapon which is more likely to be used and needed than lighting to the top of the weapon plus the "hotspot" is in line with the bullet travel path for follow up shots during recoil rather then to the side of bullet impact points and its eaiser to compensate up and down than it is to adjust side to side for follow up shots. Stay away from plastic lights, plastic mounts, mini-lights. Do not mount to the front sight or barrel unless you really have no other choice, mount on forend handguard rail at bottom 6 o'clock position.
