Well, I see yours is a little question: how many time you have to spend? ;-)
1. If you wish a WYSIWYG tool, I suggest Dreamweaver. Personally, I don't love WYSIWYG tools because I wish to have the control of the code I write. So I suggest a PHP editor (PsPad is easy, light, fast and it has very nice utilities. Look at
http://www.pspad.com/. If you want an IDE more sophisticated, I suggest Netbeans 6.8: get it at
http://netbeans.org/. Both tools are absolutely free.
2. For e-commerce you can use asp or php: as I use php I suggest this one (editor suggested are for Php, not for Asp) wich is free also. Obviously, you'll need a database: Php and MySql are a classic programming couple.
3. This is a very complex question: basically, you'll need a database wich contains products data and some php scripts wich guide your customers to choose their product and help him to buy. Then you can use PayPal to receive payements (read my article on How to implement a PayPal Buy Now button at
http://www.experts-exchange.com/A_3513-How-To-Implement-a-PayPal-Buy-Now-button-and-live-happy.html.
I suggest to read this book also: Build Your Own Database Driven Website Using PHP & MySQL by Kevin Yank (
http://www.kevinyank.com/)
I know this will not help you, but your question is real impossible to answer to ;-)
Bye
