This guide (thanks to Tealc) http://www.wiihacks.com/recommended-...s-use-run.html will tell you which ios games use to run. Read it through as it also provides the info and download links on creating your own wads if your game isn't on the list.
I was just talking to another member the other day about using a pc for storage device. In theory a wbfs formatted partition should work from a usb loader, via usb cable. I don't recommend it as I am not able to test it.
He said he had heard of people doing it awhile back but it didn't catch on. I wanted to try it but my wife will kill me if I screw up the pc. I already had to reinstall windows 7 once messing around trying to create different partitions. I know my mistake was shrinking the os drive to steal some space but still she will not let me try it again.
You can also download(place in apps folder of sd and install via homebrew) Hermes V4 and install the cios this way. Install 202 ios38 merge with 60, 222 ios38, 223 ios38 merged with 37. 202 is mainly for mplayer, 222 is for games, 223 games with instruments like RB and GH and such. ( as recommende by Baboo77, it has worked for similiar issues, and Hermes is recommended for anyone loading/playing from usb)