Processing, Arduino and water pumps question

[benonez]

 I am running a sketch in Processing 2.0 that sends MIDI out. The MIDI drives my patch in Ableton Live. It sends three control change per "frame" (this is Processing I’m talking about, so the action in my code occurs in the draw() loop, so 30 times a second the program spits out this MIDI info). So, I just want to mention that I’m not running the Arduino.ino, and want to use Processing’s Serial library to communicate with the Arduino.
OK, this is where you come in:

For my project I need to control the speed of three water pumps with the Processing sketch. I think I’m going with 120V AC pumps like this one:

http://www.ebay.com/itm/210-GPH-Submersible-Pump-Aquarium-Fish-Tank-Powerhead-Fountain-Water-Hydroponic-/251400348354?pt=LH_DefaultDomain_0&hash=item3a88a0e2c2

One solution I thought might work was to pulse a digital out pin on the Arduino and connect that to a SSR connected to the pump but I also see tutorials on using the Arduino program with a triad and an optocoupler circuit.

That’s the gist of my problem. My first question is:

Is there a solution where I can just use Processing?
Also, any ideas on pumps would be appreciated.

Thank you,
Ben