from what I was told, you just buy standard ones for a big bike. the bolts are a hair bigger diameter-wise so you have to drill the hole on the clamp a little bigger. I know BigMinis made a clamp kit but i've yet to see one pop up on here for sale.
Ive got a set of tag big bike bars with the risers that will work. I used them on my bike with zokes but went back to the pro taper xr50 bend. I like my bars high. Ive gotem listed cheap in the klx sale section.