Satrienne Rapier from the vendor is great. The Gheleon's Demise sold a couple of Iron Banners had the same perks but was slightly better because of the higher impact. I think the absolute best would be a Badger CCL with those perks (Outlaw, AP Rounds, Firefly). It has the same Impact as Gheleon's, but higher Stability for the trade off of lower range, which doesn't really matter for a Scout Rifle as they all have good range.