Is everyone smoking crack in this thread?

First of all, the Dreamcast to arcade monitor hack is very simple, and fully documented in the byoac console faq:
http://www.arcadecontrols.com/arcade_consoles.shtmlAll you do is snip one wire.
Second, since your cabinet uses a Med Res monitor (24khz), you will find that the dreamcast can NOT output that frequency (only NTSC-15khz, and VGA 31khz). Sorry but you are out of luck.
Although in this particular case swapping the monitor out with a TV is a plausabile option, its only because this is a medium res monitor. But I'd take a std res arcade monitor over a tv with s-vid anyday of the week! So probably swapping the med res monitor out for a std res monitor is a better option IMHO (otherwise you have to kludge a way to securley mount the TV in the cab).