Use what you got. I have a excavator, but no trenching attachment. No sense in renting one for 200'. Besides, I am putting this fence in something that resembles boulder field. Snake heaven.I have install some of that, not a lot but some and I would figure about the same amount of time also.
Only difference is I would get a trencher attachment for the skidsteer and use it in place of the backhoe.
www.laborready.comExcavator???? What's that............I just recently hand dug a 90' trench about 10" deep by hand through a limited access backyard for a satellite TV cable in conduit......I would have gone deeper, but between all the rocks (this is why a trencher was out of the question) and the use of the area, the homeowner said 10" was plenty. Yet another case of using what you got.......a pick axe and a shovel:thumbup: I would love to have a mini mini excavator for projects like this, but it just wouldn't pay out.