I see a lot of guys running still 170's I have three. I use hydraulics mainly but when I need gas saws that's what I use. I think toady all saws are good. Small gas saws are really cheap for what they do. Bailies supply has saw kits the also sell 1/4 pitch sprockets. Tom from T&D carvings seems bars and supplies too he's a good guy he will get your orders out on time. I was busy with the Big Buzz sorry I did not reply sooner.
Keep your saw in the Wood!