Buy one of each! No really, you should see my rigging tool box on my truck. We carry about 8 ropes everyday. I disagree that one or two ropes can dot it all. I am very particular about my rigging equipment.
I never use a pull rope to lower with. A pull rope is just that, used only for pulling. Very often you do not know how much force your apply to that rope in a pull situation. Also, the tree almost always lands on the rope. I do not want to then use that rope to rig pieces over Mr. Jones house.
We have three ropes from 1/2 and up for rigging out the tree. 1/2" true blue like Daniel said is great. Can handle some big stuff but generally is used for branches. Then we switch out to a larger 5/8th double grade for the wood or really large limbs. We also carry a 7/8th bull rope with a WLL of 32,000 pounds.
One thing to keep in mind is cycles to failure. I do not have a 32,000 pound rope because I anticipate taking a piece that large. I have it because I can take 1,000-2,000 pound pieces day in and day out and not worry about having to replace my rope every week.
So , go buy yourself a few new ropes. One of each. Just like chainsaws
View attachment 34095 . Nice to have a few of different sizes.