A way round which occurs to me is to

apt-get install grub

then swap the drives around. Grub has a really 'orrible free form syntax which I can never quite get my head around, but there's plenty of documentation out there (and the HOWTOs). The miracle is that Grub can trick Windows into thinking that it is the first drive when it isn't. Kewl, eh?

So, writing Grub to the mbr won't clobber ezdrive and Windoze can't clobber grub.