Knotical Marine Lines,LLC is a locally owned company that can take care of your needs. They use top grade three strand nylon.
They supply many of the marinas and dock companies in the area as well as supplying them with custom work.
Dave Putnam is one of the key partners and has been referred to by forum members as creating a top quality product.
Their website is:
http://knoticalmarinelines.com/
You can call them at (603) 387-9279 (From their website)
Email is:
knoticalmarinelines@comcast.net