I doubt the tolerances for that expander are tight enough to make it hold the bb consistently straight.
Just looked at your link, and for $11.99, I'm sure it won't be straight.
I've seen cones offered by guys who make motorcycle jigs that are made to fit threaded rods. They are listed on ebay a lot.
Also, you might want to contact Alex Meade
http://www.alexmeade.com/Tools.htm and see what he can do for you.