Which 3DS compatible DS flashcart should I get?

Hi,
I've been getting the urge to play DS games on my 3DS lately, but wondering which 3DS flashcart I should get...
My friend reccomends me DSTWo. I know its one of the best, (If not the best), but I'm not sure if thats neccessary to get. I really only want a cheap flashcart capable of playing DS games primarily.

I would only really invest in a DSTWO if its possible it can play 3DS games in or can use the 3DS features such as 3D, hardware features, etc etc etc, in the future.

So can anyone give me their reccomendations?

Thanks

 

Does acekard 2i have the feature where when you select it on the 3DS, it looks like the DS game you want to play?

EDIT: The other thing I was wondering is that I would buy DSTWO, but I think only if it has a chance of running 3DS roms ever, otherwise I'm just wasting money I think to just play DS roms, when soon after I'm gonna be buying another thing for 3DS roms.
Does anyone know if its possible DSTWO or acekard or anything can ever theroetically play 3DS roms?