When you head down the rebuild road be very mindful...it's really easy to get in way deep ($$$) if you want to stick all OEM parts. If you're keeping the saw for yourself well then my theory is Spend Away... I personally like knowing that I built a saw with good quality parts, and I will spend the extra on myself.
If you would want the option to sell later on and don't want to feel like you will loose your shirt than it's worth considering how much you will dump into the saw in parts, and as well (the theme of the thread) which would be OEM and which you can get away with AM. I think the most important aspect here is just being honest at time of sale what is what.
Bearings I wouldn't cheap out on... get the correct stuff or equivalent.
Cylinders & Pistons...There are some really good AM options, people shouldn't judge you necessarily for this, but with that being said the oem parts are usually the best quality
Rubbers, Intake boots, gaskets, etc... I would buy the OEM part. They are cheap generally, and of far better fit & quality
Rebuild the carb... $20, cheap, you're done
just about everything else can be found used somewhere, or new from Ebay...