Thank you all for the replies.
I like having the physical copy of a game and its case so digital downloads are out of the question, but I appreciate the idea.
I would be getting Pokemon OR/AS, Super Smash Bros. and a Zelda or Mario game (never really played either)
I've done some research on reiNAND and found that it plays game backups via the CIA format, is that right? Can I get online and play my game backups with reiNAND, or do I need to be on the latest firmware to do that? If so, this is clearly the cheapest and my most preferable option - more money for games.

If reiNAND is capable of this then gateway 3DS is redundant, right?
And as has been mentioned, if the firmware isn't down-gradable, my choices are to wait it out or buy a Sky3DS+.
Thanks again.