I was going to suggest WiiFlow too.
Unfortunately it's something I do not use and I don't know how to set it up. But that's definitely what you're looking for.
Alternatively you could just resign with Virtual Console and WiiWare games, which gets installed in the Wii Menu as Channels (like the Mii Channel, News Channel, Photo Channel) but you're limited to two things:
- Wii's Internal Memory (unless you use an emuNAND which will work exactly like a Wii Menu only limited by the space of your drive or SD Card)
- Wii's Virtual Console and WiiWare library which to be honest ain't that good if you're a picky user. Alternatively you could inject roms onto wads but compatibility depends on a lot of things. Still, games that never were in the Wii Shop Channel will work as independent channels.
I'd suggest you to use WiiFlow, it'll be easier (in comparison) and a lot safer than injecting wads and other things that requires a lot of programs just to make something a rom file and an emulator are capable to do better.
Have in mind though, there's still SNES9XGX, FCEUGX, VBAGX, GENESIS PLUSGX, MEDNAFEN, Not64, Wii64, WiiStation, RetroArch and a lot more of emulstors for different systems but that'll require a little bit more of effort setting up routes and folders....and of course... it won't look as nice as WiiFlow.