Looking for an ADC

I have been looking for this ADC208, ADC228 or ADC305 whose manufacturers are Datel. Could some one tell me a place in US especially in Dallas or Seatle where I could buy them? If it is present in India that is in Bangalore well and good my job is easy. I would like to know the price of each ADC and place where I will get these ADCs so that I could make arrangements to buy them. Thank you. With regards