So these DivX files are not AVI's?? What are they mp4's, MKV's, OGM's?
On the no cost front for AVI to SVCD you could use AVISynth (resize video to SVCD res), QueEnc (encode video), BeSweet (encode audio), bbMPEG (mux video and audio) and VCDEasy (author/burn SVCD).
Could also throw in FitCD to help with the AVISynth script and bitrate calculations.