Appreciate the advice, but the deal is done. I currently have a ton of AMBS shares in the Roth. The current tax bill on the conversion is less than 10% of the Roth value, and by the time I actually pay it, I expect it to be less than 1% of the Roth value. I don't expect to pay any taxes on this investment in the future, so an offshore trust does me no good at this point.