Which CMS is best for creating Offers sites with membership?

[mordekai]

Hi,

Please suggest an open source CMS, I am going to start an offer site - actually - "get paid to complete offers" and "a giveaway goodies".
Things that i want it to do.

*Show people offers depending on their geographic location (I should be able to configure it.)
*Track their clicks. Better if the offer page loads in separate frame than in a separate page.
*they should be only be able to proceed to the next page after they complete few offers.
*Should be able to credit money or points accordingly

these are what I am looking for

[mordekai]

please help. I have no idea how to proceed.