the Wiinja GCOS special edition should support that.
http://www.wiinja.com/utils/gcoswiinjapal.rar - PAL Version
http://www.wiinja.com/utils/gcoswiinjausa.rar - USA Version
burn the iso and boot it with your chipped wii (any chip works).
then you can select "boot dvd" and swap the disc.
haven´t tried it yet for myself, because my modchip hasn´t arrived yet.
i have another question:
must the .dol file on the 2. dvd be in the root of the dvd or can we choose a directory with GCOS. (don´t want to waste DVDRS)