Good amount of plants to start with. I started with 250 a few years ago and up to 2800 now. I agree, no need to use stainless cable, I use galv cable and it is doing fine. plus at least half the price. Be careful with natural bailing twine, if you instal your rope the middle of may and start harvest the middle to end of August the twine will rot and come on done with your plants 14 or 15 ft. tall, its a real pain in the butt trying to save them. I use a 1/4" mania rope so I can compost it the end of the season. A few rot right where the W clip holds them in the ground.
Happy growing