Control a motors speed R/F from a computer

I need to control the speed of a DC or AC motor
about a 1/4 horse and about 30,000 RPM if possible
I want to buy a total system if possible and also
write a program in C++ or Java Basic also ok it is
to rotate a small drum (dia 8" x 10 ") very small and
does not need a lot of force. I will make the mechanical
connections to the drum my self. If I can’t get a total
system I need the interface to the computer and the
software (API) to go with it I will then need a motor
I can get that