Hacking This way OR that way?

[ssskyy]

Ok, I'm gonna describe this as best I can... Which would be the correct way to buy: Console first and then flashcard second? By that I mean, I am going to purchase a 3DS console and a DSi XL console soonish (maybe from eBay, so they might not be brand new). Meanwhile though, could I order a/some flashcard/s first and have them on their way to me *** OR *** Must I wait until I get the consoles to see what software version they are on to be able to order the correct flashcard?

 

[WiiUBricker]

Just buy a card that currently works with all 3DS/DSi firmwares, for instance DSTwo. If a card is blocked it's usually a matter of days before a compatibility update is released.