Need some advice...I am just another fool trying to build a carbine that's light, accurate to 1MOA at 600 yards, and doesn't break the bank (let's say a target of roughly $1k for the complete upper).  h
Here are my questions:

1. I'm thinking 16" barrel chambered in 5.56 NATO 1/7 (chrome-lined or not, doesn't matter to me).  I know there are suppliers who sell very accurate barrels, and others that sell very lightweight barrels, but does anyone make very lightweight barrels that can consistently shoot 1MOA out to 600yds?  Or should I punt on the lightweight barrel idea and just focus on getting a high quality barrel?

2. Since I am going for light weight I would consider standard GI handguards.  Could I squeeze both the BUIS and ACOG on the upper?  How much will non-FF handguards affect my accuracy?

3. If I have to go freefloat to preserve accuracy, should I just go for the rails (I'm thinking DD 7.0 at 8.5oz for light weight) or is there any weight advantage to a non-railed FF tube?

TIA!

Anyone?  There's gotta be a bunch of people here with an opinion on this!