Deciding between Canon EOS D10 with EF300 f2.8L IS and Nikon D70 AF-S Nikkor 300 f/2.8. Have a couple of Nikkor lenses so thought I wanted the Nikon, but primarily shoot girls softball (for fun only) and many have said go Canon. Any suggestions? Also, lenses are costly; any suggestions on 200 lens with teleconverter?