Sorry. I was sacrificing small children before a black alter in hopes of reversing time back prior to Nov. 3rd....
Soooooo, my brother in crime wants to get into the AR world. And to think, just a few months ago I couldn't have GIVEN you one... LOL
The first thing you need to decide is BUILD or BUY:
You are a tinkerer by nature - and given your current collection, I would be surprised if you DIDN'T opt to build it yourself.
The first thing you need is the lower receiver - and given the size of the cartridges, you should be able to do it with a standard AR-15 lower.
Once you purchase that, then you can customize the things that you are looking for.
A 2# trigger isn't a problem - there are several choices from single stage with tuning to two stage drop ins that will get you in the ball park.
Really, buying a kit and assembling it yourself is going to be the cheapest, if you find parts these days, and the most fun since you will have direct input over what goes in your rifle.
As for a parts list, I like these guys:
Yankee Hill Machine for foreends and folding sights.
RRA NM 2-Stage Trigger. Best drop in trigger for the money. Period.
Jard Adjustable Triggers. Great for the do it yourselfer.
Magpul PMags are the current Need To Have accessory for the "tactically sound" community.
CMMG SSAT Magazines are another choice that have great reviews.
Hit me up if you have any questions or need some advice on parts and where to get them...
JD