Chainsaws

Hi there, I don't know much about chainsaws except they cut down trees!

I need to get a new bar, and a new chain for my Rancher 455. Browsing the Husqvarna site, there are several options.

I use this chainsaw to cut down trees of all sizes, some Oaks up to 70' tall. I also use it to trim up the branches and trunks after the tree comes down.

Not sure if that helps when selecting what chain size, but that is what I use it for. There are too many options for a guy like me. I just want whatever bar & chain came with the saw originally, or something close to it. I don't want to get caught up in 1.3 vs. 1.5 mm, etc. Please just make a recommendation!

Thanks!