Okay, I don't mean to offend mauifrog by this, but I prefer modmii, and it is what I would recommend for noobs. I would recommend updating to 4.2. But, you don't have to update officially. To load USB Backups, you really don't need the trucha bug installed on the IOS's or all that crap. All you need is d2x cIOS and CFG Loader.
Also, I would actually not recommend using WBFS with USB Loader GX, and actually instead recommend you use FAT32 and CFG Loader. The wads you can load with Mighty Channels, SNEEK, or just install on to Wii. I'm not sure if the wads and stuff can be stored on 2 gb sd card, I would just recommend running it all off of the USB Drive (If you use FAT homebrew and wads can be stored too). You could probably fit some wads and homebrew in, but the ISO's can be fairly large (even after being scrubbed). Also, you can always just install the Wads onto your actual wii, making them very easy to launch.
Also, I would actually not recommend using WBFS with USB Loader GX, and actually instead recommend you use FAT32 and CFG Loader. The wads you can load with Mighty Channels, SNEEK, or just install on to Wii. I'm not sure if the wads and stuff can be stored on 2 gb sd card, I would just recommend running it all off of the USB Drive (If you use FAT homebrew and wads can be stored too). You could probably fit some wads and homebrew in, but the ISO's can be fairly large (even after being scrubbed). Also, you can always just install the Wads onto your actual wii, making them very easy to launch.