How much mainsail area can be put on a 24' mast?
I want to have as much sail area in the main as is reasonably useful, to help balance the rig. Also because the reacher will be furled going upwind and in strong airs.

This directly correlates to which mainsheet system to use.
I am looking at the Harken 2.25" Low-Profile Mainsheet systems, specifically the 5:1 and 6:1 versions
Murray's Catalog of Mainsheet Systems

Also, what are the best (reasonably priced) lines to use? The 2.25" blocks necessitate a 3/8" line. I like to use a continuous line for both the mainsheet and traveler systems.