Re: AR question
You could try calling each of the manufactures or emailing them explaining what your looking for and let them tell you what they offer that fits your needs. Take the info, weigh cost and offerings. Then go from there.
Search the net for who offers that particular rifle and the prices.
With out more info it's really a vague topic with way too many variables.
Such as are you willing to do minor assembling yourself? Possibly assembly your own lower receiver?
Which is rather easy and allows you to set it up to your liking and dictate the weight and performance based upon the parts you select.
What length barrel and type of gas system you looking for?
The intended use of the rifle?
Details such as these help us give you a better answer to your question.
It's all about the details...
If you haven't figured these details out yet I suggest doing some research and find these answers and ask a more detailed question. I've been here done that kinda thing is the only reason I ask these questions and suggest this action. Just my humble opinion.
I spent 6 months reading and researching before I built my first rifle. Less then 6 months later I built my second and I'm on a third 3 months after that...
Heck it's legos for adults basically and addictive as hell!
Good luck!
Wish I could just answer the question but with out more info it's up in the air.