to start off i have a wii 4.2u

i have been reading through this guide

i was wondering about installing bootmii as boot2 or an ios, what is the difference and will i do all this on the wii.

once i install the HBC is everything i need on the wii to run backups and usb loaders.

i have been reading so much that im starting to get confused and unsure of myself, thanks.