I just wonder... I was afraid of rigging, once. But then I read Des's instructions, found your web shop with instructions, with eyelets and tubes available. And suddenly rigging became my favourite piece of this hobby. I suppose, that well explained process and availability of just eyelets and tubes will make the feared process easy for anybody. I do not personally see the point in preparing such ready to rig pieces. IMHO there are too many unknowns, starting with the line length, ending with type of the end fitting - exactly what you ask about. I do not see a simple answer to these questions. If I were you, I would focus on making eyelets and tubes available. They are so universal, that any rigging type can be done without any problems.
Just my 3 cents, of course, I am curious what others will say.