I personally have AR 8 mags in a BOB, 8 mags in my chest rig, and 8 mags in my ruck giving me 240rds no matter what I grab to go. I designed it this way to be standard across the board. Now I need more pistol mags because I intend on doing the same for it as I did my AR, I just wish the pistol mags cost the same as a P-mag. lol
As far as mags and lights go, it really goes back to what you need for your "mission." You never said if you carry pistol mags in your EDC setup. If so get a few of those first in case something goes wrong with the ones you have. Also, if you have a hand held light you could hold off on mounted lights at first. As far as a pistol mounted light... do you have a way to carry it with the light or is this just going to be a nightstand gun that wont see a holster? If you don't have a way to carry it with a light attached right now I say get a hand held light for your pocket and then a mount for your rifle (like this, or this). That will help you cover two guns with one purchase and will set you up nicely until you can get a good pistol light and/or holster to carry it in. I would hold off on AR mags until you know how many you can carry in your LBG. If you can load that up nicely, I say hold off on AR mags until last.thanks a lot for the input guys. this has been helping me alot especially with prioritizing my needs first. after thinking about it the LBG id defintely going to be first followed by a sling. now just try to convince me on the last 4