With a 1/3 acre of lawn you will probably never really use the extra durability of the commercial Toro, but if it is what you want it will certainly do the job for you. You might also look at the higher end Hondas, namely, the HRX. They usually run about $600 from dealers around me. Some of the people on this board have used them in commercial applications with good success. Another alternative would be to go with a reliable push mower if you can do without self propel which sounds like a possibility since you have to maneuver around a lot of obstacles. I would look at a used Lawnboy two-stroke. Reliable engine and the older ones are very light and easy to push. They should run you less than $300 in good condition.
Scag Tiger Cat 48-inch deck, Kawasaki motor
Lawnboy 10227 2T push mower
Stihl BG86 handheld blower
Stihl BR550 backpack blower
Stihl KM110R kombi system with lots of attachments
Stihl HS45 hedge trimmer 24-inch blades
Echo SRM210 trimmer