Hardware SD card for Gamecube saves?

[superspence]

I have a GC memory card that is out of space so instead of buying a new one I want to be able to use my SD card for saves. Would it be possible to modify one of my current memory cards? Or could I buy something like this for my Gamecube. It says it needs special software that appears to need an Action Replay for GC, which I don't have and am kind of unwilling to buy, seeing as it would be cheaper to just buy another memory card.

Thanks in advance!