Looking for 20in styainless fluted upper, not a full bull though.  front gas block with a rail so can mount a flip front sight and use throw lever rings on the flat top.  anyone recommend a good manf ?  Would like to stay < $600

I was looking at RRA uppers, but I dont want a bull barrel upper, and all the other uppers have the standard A2 front sight block.

[edited to add]
actually I kinda like the RRA A4 upper in stainless, maybe I can just replace the front sight block ?

Bushmaster will flute the barrel.

20" upper

20" V-Match

Take a look at the options pulldown on the page.  I don't know if they'll do stainless, but I'd give them a call to find out.  I'm pretty sure they'll install a different gas block during assembly if you ask them.