Of those listed the EOS 500D would provide you with the most flexibility to quickly build upon in the future. Remember that, although there's no reason you couldn't produce and sell images/have a business based on the 500D, the lenses you're likely to want to attach to the camera make a significant difference to the shots that you can obtain. Never underestimate the overall cost that this can bring to your initial package. Start it up as a hobby, have fun with making and sharing images, then see where you go from there.
Originally Posted by Sallyann