I'd say controller is definitely viable. All in all, whatever peripheral works for you is all dependent on how much time you put into playing and practicing with it.
Example, I've been using an arcade stick for fighting games post Street Fighter IV, but before that game came out, I used a PS2 pad. The GG XX series was a series of games that I played on pad primarily prior to SF4. So, GG Xrd comes out and I started playing it on a stick. I was doing OK, but I was having trouble performing certain motions. So much trouble, that it cost me a lot of online matches.
So, I went back to a pad, and I found myself performing much better. Go figure? Either way, just keep practicing. Stick or pad, your performance will just depend on your amount of practice with it. Since I played GG on a pad for so many years prior, I seem to play it much better on a pad then I do a stick, even though I've been using sticks on many different fighting games ever since 2009.
