Need Help.

I was about to buy the Nintendo ds fat version but the problem is that its in Japanese language and its the last stock. if i buy it, will the USA cartridge and flash cart (EDGE) will work on the japan nds fat version?

you can change the language i believe. but yeah, you can use english games on it and your edge card aswell. since the ds fat is not region locked

Yes, and DSi only region-locks DSi-enhanced games...

Really? Will there be an option if you want to change to language before you edit the rest of the menu?