@90Ninety it is not exclusive, you can use USB Loaders and Emunand. I myself am using USB Loader GX and got almost perfect compatibility for all Wii titles and GameCube games. WiiWare and VC took me longer, but I have managed to run all I have tried, in one way or another. Some of them run through 'Full' emunand emulation, some I needed to use 'Neek' mode, but always from USBLoaderGx.
First question, do you have a dumped nand somewhere in your SD card? (normally it is under 'sd:/nands/pl_xx' [xx= eu, us or jp]). If not, emunand will not work. You can either dump your own nand to a file, or create an emunand using ModMii (option install NEEK+create nand). If you need more detailed instructions on how to do it, answer this post or pm me.
Now, how to get Neek mode up and running? Starting from
your current installation, I would do this:
1) Create a 'sd:/wbfs' folder.
2) Try to start Neek2o using the channel.
If it does not work,
3) Remove the file '/sneek/di.bin', or move it somewhere else.
4) Try again to start Neek2o using the channel.
If it still does not work,
5) Delete the folder 'sd:/sneek'.
6) In ModMii, select the options UNeek + DI instead.
7) Copy the files from ModMii (copy_to_sd and copy_to_usb) to the sd/usb.
8) Copy the emunand from the SD card to the usb drive (if you had it in 'sd:/nands/pl_eu' move it to 'usb:/nands/pl_eu')
9) Try to start Neek2o using the channel
This last option is what worked for me. For what I have seen, UNEEK is much easier to get up and running than SNEEK.
Once you get the emunand to work, rest is as easy as to configure the wiiware/VC titles depending on its compatibility.
It is important to note, most of the wiiware/VC titles will black screen if they are from other regions, even after patching them via Freethewads, ShowMiiWads or using Priiloader Region Free all, therefore it is a good idea to have a second Emunand for those games from different regions (or three, if you also want to access JP titles).
I can explain how I am using two emunands from USBLoaderGX to start all WiiWare / VC titles without issues and without need to change the path if someone is interested, but I will leave that for another post.
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USBLoaderGX has an integrated WAD manager, so you do can install VC and Wiiware via USBLoaderGx (Settings -> Features -> Emunand wad manager).
No you don't require Neek. USBLoaderGx has an embedded nand emulator, and it works well but has limited compatibility, therefore it is advisable to have Neek installed as well.
USBLoaderGx can also run WW/VC titles in 'Neek' mode, by just changing one setting for those titles not compatible with the embedded emunand.