I really think an emulator is a hella lot more convenient and reliable but do what you want.
In fact, before I knew emulators were a thing, I considered getting a Gameboy Advance myself to play Pokemon Sapphire but obviously called that off after I found GBA4iOS.
Also don't really bother with the DS. The Pokemon games for it aren't really that great.
Honestly my best memories with the DS had to be with Mario Kart 7. Tears were shed, friendships were broken.