For a gala I did I controlled 70 Pinspots off 3 wall dimmer switches. I was told by the guy who got these switches that they were rated to 1KW. Head to the hardware store and ask what the switches are rated to. I'm sure you can find one.
By the way, they get INCREDIBLY hot when under this much load. If they are not in the wall like they are designed to be, be careful of the backside. I needed to make a gaff-tape type handle because I would accidently hit my hand on the underside of the switch (what would be in the wall).
EDIT: Ok, it was somewhat of an exaggeration, incredibly hot. However, it is hot enough to cause a fair bit of pain when you touch the back of it.
Use double deep plastic single gang boxes built into a wood frame so you don't burn yourself or anything else.(I am not saying to do this or that it is safe/legal) the user assumes all liability associated with such a device!