Profile makes a "euro" BB for BMX now. Before about 6 years ago BMX bikes had to PRESS their BBs in. Now they screw in like road/mtb. When that transition happened, they made BBs to mate with the BMX crank arms and chainwheels.

Maybe try this for your setup (make sure to choose the "European" BB option: http://www.profileracing.com/loader....&productid=118

I'm sure that you can contact Profile and get the width of the BB spindle. They are a cool group of folks.

That bike isn't mine. It belongs to "Big Dog" a messer in Baltimore. But, this pic shows that your idea will definitely work.