Sterling Accessory Cord is probably somewhat ideal for your weight specs while still being a reasonable price. Stronger than what you are looking and from a very reputable brand. I use sterling accessory cord all the time; it is a staple in my whitewater kayaking rescue kit for prussics. They have a bunch of sizes, but here are three in your general strength area.
- 4mm cord is 876lbs break strength
- 5mm cord is 1,169lbs break strength
- 6mm cord is 1,978lbs break strength
In regards to hammocking, remember that the break strength of the rope and the ability for it to support a hammock are VERY different. When using rope to support a hammock it is at an angle which greatly reduces load capacity (45 degrees is a 40% increase in load for example). When setting up for a hammock you are also going to have knots. Knots again will greatly reduce your load capacity (50+% easily). You are also moving up and down when you get in which increases the load on the line. I personally wouldn't hammock on anything rated below 1750lbs (so the 6mm would be fine). All the talk about weight aside, DON'T HAMMOCK ON PLAIN CORD because it is bad for the trees. You should be using webbing, or at least put something between the trees and the cord.