Currently, Kodak is the only company that commercially sells Super 8 film in the United States (as of August 2010). The Czech company FOMA continues to make double-Super-8 reversal black and white film, but it currently does not sell its film online in America. Kodak sells Super 8 film cartridges through its website or a phone number (800-621-FILM). A small number of camera shops also stock Kodak Super 8 film.
Kodak currently (as of August 2010) sells the following varieties of Super 8 film in five-pack minimums:
EKTACHROME 100D Color Reversal Film 7285: Color reversal film increases the amount of contrast and grain and offers more lush, saturated color. It is balanced for daylight illumination and speed-rated for 100 ISO. Super 8 enthusiasts often pick this sort of film to embrace the higher-contrast, surreal attributes that color reversal film allows.
VISION3 500T Color Negative Film 7219: This film is optimized for capturing shadow detail and minimizing grain in low light. It can also perform well in bright light without overexposing. It is speed-rated for 500 ISO in Tungsten light.
VISION3 200T Color Negative Film 7213: This film is used for versatility. It performs well in many challenging situations, and it is designed to have a minimal rate of failure. It is speed-rated for 100 ISO.
TRI-X REVERSAL FILM 7266: This is a panchromatic black-and-white film designed to cater to indoor light situations. It also will perform adequately in exterior daylight. It is rated for 100 ISO.
None of these film stocks feature sound. To obtain Super 8 film cartridges that will allow you to record sound, you will have to pursue an avenue such as eBay to find vintage stocks.
Currently Kodak does not offer Super 8 processing. A1 Film labs in New York City is a popular processor. A1 will put your film on DVD if requested. Alternately, certain camera shops will process and develop Super 8 film as if it is 35 mm. Ask around, and you may find what you need.