Hi Guys,

I want to develop a clone website of http://www.satellitetvtopc.com
with better presentation, layout, content and payment pages integration with clickbank.com to accept payments through credit cards as per their standard guidelines.

Website major features

01: Website SEO
02: Downloadable Software to view channels on PC anywhere from world by the user after make the payment online and Bonus 1 to Bonus 4

03: Product Management
04: There will be three products

a) three month subscription
b) six month subscription
c) One year subscription

05: payment pages integration with clickbank.com

I also wanted to know is there any online service available to Play the Tv chanels

 Any suggestion will be highly appreciated.

I feel that I have to reiterate the fact that you will indeed need to invest in a little development to get done.  However, as the previous posted pointed out, if you go with DotNetNuke, you already are starting with the majority of your code done.  In order to get everything else you need to work, you will need to build or buy new providers and/or modules. 

However, make sure that if you do move forward with DNN, do not change the core code if at all possible.  Doing so may make it completely impossible to upgrade later to take advantage of new features or security updates in future releases.  If you opt to change the core code, you are essentially putting yourself in charge of security monitoring, bug changes, and feature updates down the road. 

I am not sure about the satellite question...  But the answer to your W3C and SEO question is mostly.  There are many areas where improvements need to be made, incuding in the DNN Core Assembly.  There are many updates coming to fix these issues in Cambrian.  I feel I should also point out that although there are improvements needed, the existing issues are not bad enough to keep your site from being indexed properly or even getting a high page rank. I have a client I am working for right now that has a PageRank of 1, and the main thing that they did for SEO (besides valid content) was write a custom URL Rewriter Module.