Square-Rigging System for Sail Boat - Info, Please

[Jolly Roger]

The OP’s original question was whether a “kit,” was available for a square sail on a modern sailboat. I presume he means something like a roller furling headsail kit, and having delved into it in-depth myself, I can safely say there is none. The principal reason is a lack of interest from the sailing fraternity, which results in a lack of commercial viability for a manufacturer.
That’s why I designed and built a system for myself.
Anyone who has handled traditional squaresails, knows the complications associated with running them. Principally, the problems of furling, unfurling and reefing from the yard, not to mention having a crew who are prepared to get up there in the first place.
I have solved these problems with my roller-furling square-sail system, and the advantages far outway the disadvantages. These are explained on the home page and others on my website, in great detail.
Anyone wishing to have such a system has two choices; they can pay someone to make it for them, or make it themselves.