first, are you SURE this monitor can scan down to 15 Hz? the page you gave says on the specs that it is Horizontal 28k - 80kHz; Vertical 48 -75Hz...
either which way, a VGA to DVI will work fine for the CVPPC and most likely the P-IV. I've used them on many many diff. setups without a problem OR resolution loss.
So I wouldn't run those other methods, you'd just end up with poor quality graphics...