i also have a similar setup i dont know why i didnt say it
i have a 24" monitor that i also use for my consoles
pc hooked to dvi (1920x1200)
360 on hdmi (1080p)
wii on component (480p)
ps2 on s video (dont know dont care)
being that there are no speakers on my monitor i have some nice computer speakers that i use for everything and control with one of those silly video selector things
everything looks really nice and works fine