Welcome to Arboristsite!
To answer your question in a word: neither. Top handle saws are generally viewed as poor choices for anything except off-the-ground work; I am presuming that the bulk of your cutting will occur with your feet planted firmly on the ground. The issue of the proper market for top handle saws was recently debated in depth here:
http://arboristsite.com/showthread.php?t=32647
A small saw with a conventional handle will likely be a better all-around saw choice. Echo CS-346, Stihl MS170/MS180, Dolmar PS401 spring to mind as excellent choices in durable small saws.
If you are still hell-bent on purchasing a top handle saw, you will likely be content with either, with the edge possibly going to the Echo for rugged durability (they may not be the fastest saw on the block, but you can't kill Echo saws) and the edge on light weight to the Stihl.
And yes, you can probalby get parts for your saw. Folks on this board seem able to find parts for darned-near anything, so ask around.