You are a braver man than I! I'm going to be in a state of paralysis regarding headers and save files and... TWO BUTTONS! Seriously though, I'm so screwed. I seem to be the odd man out on this board. The n00b thread is just so friggin crowded...
Well the fact is that you can't get a private header without an exploitable 3DS. (<9.2) OR a Powersave.
It's not that hard, everything is available on internet and there are lots of tutorials.
I used the exploitable 3DS method with GW launcher on a 9.2 system. (My own 3DS is 9.9 because it is a new 3DS that was shipped on 9.5 but my sister's one is 9.2)