for the V device I use 1 inch nylon block with small drill size near the kite and larger size drill near the bar so the flag out line stops at the block. Also two big holes for chicken line.
if u want a stopper ball just buy one from a marine supply store they have plenty in all sizes
I take some kite line lark's head it and then sew it down 10 meters from the bar. It works the same as a stopper ball and less likely to snag.
If you want a spinner I think Naish sells one seperately from their bars.