When you chose MPEG 1 VCD as the `Convert to Format', the Properties page greys out because the standard properties for making a VCD in MPEG 1 format are listed and you cannot change them.
Digital Media Converter has a Custom MPEG 1 option. If you chose this as the conversion format, you can change Properties like Video Dimension, Frame Rate, Audio Bitrate and Audio Frequency to suit your requirements.