i was thinking of doing the same thing,
but after looking at the can and seeing all the spot welds and lumps and bumps of the internal's decided not to.
btw you can weld stainless with a mig welder using the same wire as mild steel, all that will happen is the welds will rust and the can will not.

instead i ordered Leo Vince exhausts on Friday 09/10/09 From http://www.motorcycle-exhausts.co.uk/ turned up on Monday 12/10/09.

can wait to fit them.