TBH you can buy whatever bars and chains you want so long as the size is correct for your model. I use laser laminated bars and their aggressive chains because I don't want to be out there all day when I'm just going to burn the wood in a year. I didn't even know premix gas was a thing. I just buy ethanol free gas and add oil to it. Stihl kinda got me on my string trimmer where if I bought a 6 pack of their preferred oil they extended the warranty by 3 years for the $15 it cost.