Rigging Suppliers

These companies are recommended by boaters for rigging supplies

http://www.sailingservices.com/

http://www.macksails.com/

www.riggingonly.com

http://www.velasailingsupply.com/Harken_Cruising_Furlers_Toggle_Assemblies_Adaptors_s/2203.htm

https://www.americanriggingsupply.com/index.htm

Has anyone here beefed up their rigging from factory specs?  I need new rigging and am soon to be sailing in the Gulf, and was wondering if beefing it up a size for at least the head and back stay has been tried by anyone, and if so, have you had any luck with it?

I got a copy of "This Old Boat" thinking there is much to be learned.  One thing it talks about is the fact the most of the rigging has gone to metric due to a limited world market and economies of scale.  I'd go to the next larger metric size you can find. It will be stronger and easier to get parts for.  This is identified as a real plus for people who are cruising far reaches of the world.  This probably doesn't inclue the majority of Clippers