FarmerSid,
If it's one saw, for your wood range, I'd buy a a 60cc in the Stihl 362, Dolmar 6100 or Husky 562. If you have the coin to swing two, buy a nice used 346xp or a new Husky 550xp/Jonsered 2250, or Stihl MS 261CM and a Husky 372xp, Stihl MS441 or MS461, or a Dolmar 7901/7910. A stock or modded 60cc saw is hard to beat as an only saw. A ported 60cc saw will cut right with and sometimes past the 70cc saws. From both a durability and production standpoint however, I'd vote for a 50cc/70cc combo, as in that wood, the 50cc saw will get a lot of your cutting done with a smile on your face from the lack of fuel burn and back pain. The 70cc saw will likely be a bit more durable in the bigger stuff and can run a 28" bar if need be. I have a 9010 coming to me soon, that I can't wait to play with but the 261 and 562 are the 2 that get the most use right now, regardless of what size tree I'm cutting. When I had my 346, it did a lot of work that the 039 had done previously as it was that zippy and quickly became favorite saw of both my Father and myself.
Good luck with your decisions!