This whole statement has me a bit confused. I assume you are wanting to do the following?
You have a OLD 3DS. you want as multiregion. ( Luma CFW / B9 does this )
You want to buy a n3ds / n2ds and install CFW for vc injection?
I have a New 2DSXL, and I'm going to leave that alone. I'm trying to save for the SNES edition of the New 3DSXL, which I will also be leaving alone. I have a black 3DSXL, and THAT is what I want a region mod for. I'd try to do it myself, but I don't trust my skills, since I've never done mods of any kind before.