Sous vide with a slow cooker?

I've been intrigued by sous vide cooking, but I don't have any inclination to play with arduino(?) controllers or wire/solder anything.

Is there any reason you couldn't use an older (non-digital) slow cooker/crockpot with a Lutron dimmer cord?  We use the dimmers on all our bedside reading lamps, but they're rated for up to 300 watts.  It would take some experimenting to get the temperature right, then I think I'd tape a "stop" on the slider switch at that point. 

Any thoughts?  Raising the food from the bottom of the pot?  An upside-down silicone cake pan, maybe?  Or suspending the bag somehow?  I already have a Foodsaver.

I'd be happy to hear any thought or suggestions.

http://www.amazon.com/gp/product/B0000DI241/ref=pd_lpo_k2_dp_sr_2?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B0000BYEF9&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0WRPJ5W9TWM39K9Z1Y9N