stihl ms291

Looking for a head and piston for ms291. Would like aftermarket if available.

I picked up a complete MS291 for sale in a box completely disassembled because the piston has a hole in it, for $50 today. I want to put it back together. I was looking around for parts I'll need to order and I saw some posts about upgrading an MS290 to MS390 by replacing the entire short block...

So, I am looking for a new machine, my poulan pro bit the dust the other day, and I have been advised (based on budget and usage) to go for either an Echo CS490, stihl MS250, or Stihl MS291. I decided to do a little bit of reading about theses machines, and I have not found alot of helpful...