yes its possible to use a wifi router as an access point...that's exactly
how i have mine set-up.
tbh, why not just buy a wireless router and be done with the "wired" router?
wireless routers also have (normally anyway) 4 ethernet ports to connect
pc's via ethernet, so this would pacify your dad. they also (obviously) have
wifi capability so you could connect the Wii wirelessly.
the good thing is, you don't have to have a pc switched if you want to
access the net with the Wii. they all use the internet via the router
independantly of each other.
check the "router" sticky at the top of the forum list for routers which
are compatible with the Wii.