email mike at sportsrant.com, or go to
www.sportsrant.com to check it out. This is exactly what you're looking for. I have it on my sports related site, but am not currently using it.
VBpool is what you are looking for. I have it for my site. It could use some customization, but it's the perfect program, basically just like a yahoo style u pick 'em , by spread or s/u.
If anyone wants to pay to have truely "private" pools, and a paypal subs thing added in, I would be more than happy to pitch in on that.