You seem to imply having it all prepared for you, and in that case I have no suggestion. Replacing my running rigging
is one of my favorite activities and I do it all myself. The splicing is such a rewarding skill, and the cost is so very much cheaper. It is one of the most unique sailor activities, as opposed to the common boat stuff of fiberglass love and diesel maintenance.
I source my line
from both Fisheries Supply Fisheries Supply - Marine Supplies Since 1928
here in Seattle, and sometimes an outfit in Bellingham, WA called LFS marine Marine Hardware, Mustang
Survival Gear, Grundens Raingear, Scotty Downriggers & More! - LFS Marine and Outdoor. Both have good prices.