I would not do that because they would not buy you anything but complexity. Can't use either hand, can't steady the stick between your legs, may still need an arm rest. If you are going to change something, you might as well get something in return.
See N64KR at http://KR-Builder.org - Then click on the pics There is a time for building and a time for FLYING and the time for building has expired. Daniel R. Heath - Columbia, SC See you in Mt. Vernon - 2005 - KR Gathering Why not the best of both worlds, go with dual side sticks.
