I'm from TX, the home of the combo bike shop/power equipment shop, I sold and serviced this stuff at the first bike shop I worked in. I would buy from a shop that can service them, not a big box.

If you want to use a blade, get a straight shaft trimmer. They are heavier duty than the curved models. Good gas, the right oil mix and fuel stabilizer will go a long way to keeping it running. I'd guess out there you don't really have an off-season for growth, but if you do think it will be idle for awhile, run all the gas out. Stihl, Echo, Honda, Husquavarna are all good brands.