+1 for Rainer arms. Very lightweight. Very secsi.
If you are willing to change out the gas block to a low profile one, you can get a longer free floating tube.
But for a Stag model 3, the cheapest and fastest option would be to get a gas block height front sight, either fixed or folding, and put it on top of your gas block. Get a metal unit, MBUS's will melt.
Assumption is the mother of all ****ups.
Know what you know, Know what you don't know. -Paul Pedzolt
"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul