Hmm well I suggest just trying this guide and doing the offline guide up to step 10
http://gbatemp.net/index.php?showtopic=144835
Do you already have the homebrew channel from whatever else you did? You can skip steps 4-8 if you do.
If you don't then do 4-8 and skip A-B.
I'm thinking your problem may be not having done this step?
B) Run WAD Manager choose IOS35 and install IOS35-64-v1040.wad then restart
Anyways just try following that guide up to step 10 and you should have everything you need to run any usb loaders. There shouldn't be a problem with what you've done so far Just remember that 1 TB is overkill for wii games so you might want to partition your hard drive so you can use it for other stuff as well since the wii needs to format at least a partition of it to WBFS which isn't a file system that anything else will read for stuff other than wii games. So partition off what you want for the your games and leave the rest for normal use (guesstimate your wanted space by multiplying the number of games you expect to be putting on it down the line by about 3GB.)
Edit: Also since you have a launch wii you should be able to install bootmii to boot2. I would suggest doing this first before you continue in case something goes wrong. Go to bootmii.org and grab the hackmii installer. Rename the installer.elf file to boot.elf and if you have the homebrew channel then put that boot.elf file in a "hackmii installer" folder in your "apps" folder of your sd card, then run the hbc and run that hackmii installer to install bootmii to boot2 and IOS and the updated HBC. (Alternatively if you have a relatively recent HBC and wifi I think it may auto prompt you to run the hackmii installer to update it.) Once you install bootmii to boot2, when you reboot your wii the bootmii menu should come up instead of your system menu. Then use a GC controller to control it (or if you don't have one, use the power button on your system to go right and the reset button to select. Then click the 4th icon and then the first one. This should prompt you to backup your Wii's NAND to your sd card (which needs to have at least 540ish MB free on it.) if your card has that much space do that and let it backup your nand and let it verify it afterwards.
If you do that your wii will be pretty much 100% brick proof. If you don't want it to boot up to bootmii at the start anymore after that just rename the bootmii folder to something else on your sd card. Then continue to do whatever else you need as I said above.