I'm not sure about that roach build.... I mean it sounds OK at first, providing you get a few lings aswell. Like the lings will take care of his lings and your roaches will own the banelings + absorb the splash damage.
However, I think the reality of it will be (unless you have boxer micro) that your lings will still get raped by a few baneling explosions and his lings will dominate your roaches. Roaches suck against lings so bad, their rate of fire is just too slow imo. Admittedly, I play about one ZvZ a year, so I'm in no position to really speak that much on it. I do see the pros go baneling/ling vs baneling/ling a LOT though, and I think there's a good reason for it.