No, you want to update to 4.1U. Then you get the latest features and bugfixes without all the drawbacks of 4.2/4.3. I have no idea why that guide has you install 4.2, because there is no point in it unless you want an inferior softmod.
I don't know what drawbacks you're referring to. Exactly how is it inferior?
I find 4.3 the easiest to softmod. It doesn't require you to play a game before copying a save from an sd card & it already has IOS58 installed so you only have to install HBC once. Plus HBC can see your USB hard drive, so no need to copy stuff onto the SD card.
The only problem I can see is the korean wii issue, it's not something I think about. I'm suprised nobody has ever done a mod that removes the korean key, so you don't need any patches. That would be much safer.