In this situation I would say that a fan controller is not necessary.
No, but it's cool as hell ! :-)
However, if I were you, I wouldn't buy a touch fan controller, especially a 25$ one. They are very hard to control and the "touch" response is usually awful.
I'd go with a Lamptron
or the Scythe Kaze Master Pro
. I've got the Kaze Master Pro and I'm very happy with my purchase, but I've got 12 fans in my PC. If you only have a couple of fans, then it's totally useless.
Also, 10W per channel should be more than enough, unless you want to chain multiple 38mm thick fans on one channel.
Good shopping !