first of all welcome This would be the guide you would use
Just follow the instructions word for word... You do not need to update to 4.3, 4.2 and 4.3 updates were mainly to stop the hacking. You should be able to load Priiloader as a boot2. Make sure you do a backup of your nand, so just in case something unfortunate should happen, you will have a way to restore your wii.
If you have any questions you can always pm me, i have done over 25 softmods and can help you with the basic installation.