Amsteel Lifelines

I'm planning to replace my vinyl coated lifelines with Amsteel and had several questions.

Do most use 1/4" or 5/16"? The stanchions will accomodate the larger line, so I'm leaning toward it thinking it may last longer. Any thoughts?

On the ends, I'm planning to put thimbles in the eye's. Is that the usual practice?

Lastly, what's a good target length for the lashings?

Thanks,
Doug