Re: larue stealth upper???
Build your own upper.Some companies do things better than others,by doing it yourself,you can pick and choose from barrels,upper receiver,BCG,handguards,muzzle attachments,BUIS,etc.
My upper I just started is a Vltor VIS rifle length,Centurion Arms 18" MK12 barrel,LMT enhanced bolt(have not picked a carrier yet),may go with a PRI gas buster charging handle(need to do more reasearch)as it will be used with a suppressor 50% of the time,Smith Vortex flash hider.Noveske switch block.
Shop around and do your research,it is a lot of fun to do it yourself and you are not stuck with what a company sells in a package deal.JMHO.