I'm building up a Stag lower (probably with ACE skeleton stock).

What I think I want from an upper:  (M4gery)

Flattop with flip up rear sight (will be used with EOtech or possible Aimpoint CompM3)
1:9 chrome lined barrel
Free float railed forend with forward pistol grip
Weapon light (activated by front grip?)
Magpul rail ladders

not sure about front sight (flip up or standard?)
want to cowitness with EOtech?  do I need some riser ? ( I would prefer not)

What rear sight?
What front sight?
What rail /light system?

Cost is not a critical issue.

What do you recommend?

Stag upper with a denny gun 16 mid length barrel with a yhm light weight quad rail

Quoted: Stag upper with a denny gun 16 mid length barrel with a yhm light weight LaRue quad rail

price not an issue, huh?

Quoted: denny gun 16 mid length barrel

please clarify "denny gun"

What is he big deal with EOthingys and BUIS? Get an A2 and learn how to shoot.

Quoted: What is he big deal with EOthingys and BUIS? Get an A2 and learn how to shoot.

Umm,
a BUIS provides your "A2 and learn to shoot" idea.
it's the 21st century...a dot optic is perfectly acceptable for general use.
of course a BackUpIS should always be mastered as well, but there is nothing wrong
with using advanced sight aids.

If it helps you hit your target...

Quoted: Quoted: What is he big deal with EOthingys and BUIS? Get an A2 and learn how to shoot. Umm, a BUIS provides your "A2 and learn to shoot" idea. it's the 21st century...a dot optic is perfectly acceptable for general use. of course a BackUpIS should always be mastered as well, but there is nothing wrong with using advanced sight aids. If it helps you hit your target...

+1
A2s are the best for opens imo, but optics and BUIS still work and provide more options