I have a friend who is a DJ, I’ll ask him what he uses(hadn’t even crossed my mind to ask him). But I suspect, like the program you linked, it’ll be over priced for my trivial needs.
Dual programs running, one with video and one with the music would roughly work. No one but me would know that the real music videos weren’t occasionally playing (But it would still nag me knowing that there has to be some way to pull it off.)
It seems like it would be ideal for a WMP visualization plug-in. Simply playing random video instead of the cheezy line art. I’ll keep digging around and trying more search terms on Google to see what I can find.