The answer to the OP is easy. Stick with an independent dealer with a big service/parts department. What they carry is what you want: a long term service relationship.
The same "brand" at the box stores is not the same product as carried by dealers whose commercial customers expect real performance.
And I'd rather have a backpack. At idle they put out more than my handheld Stihl at WOT. Cleaning the street, the alleway, the roof, the gutters, the clothes dryer vent, the car HVAC vents, etc . . . you wouldn't be sorry to have the backpack, IMO.
And use only OPTI-LUBE XPD oil.