Basic questions about developing a dial-out asterisk app

Hi,

First, I apologize that I know very little about internet telephony.

What I’d like to do is very simple: connect two or more people in a conference call with a dial-out feature. As I’d need to do hundreds of such calls in a day, some simultaneously, I don’t want to buy any expensive equipment and would prefer that I use some hosted (VOIP?) servers somewhere to make the actual connections. I don’t need any incoming calls, just the outgoing ones I described. Further, I want one of the participants to be the “lead” so that if they terminate the call, the whole conference is terminated. I would like this connection to be made with a simple web API that as myapp.com/%first number%second number%third number … plus with some security passcodes.

I’m not looking for anyone to post actual asterisk code to do this, but was wondering if this is even possible, what equipment, if any, I need, and what the overall handshaking process is, what you’d expect the cost to be for development, and if you have any recommendations for which VOIP service providers to use. Again, my apologies for lack of knowledge in this area, but I’m sure someone out there knows this area well.

If you are actually an asterisk developer and are interested in bidding for this project please let me know and we can work from there.

Thanks so much!

Armand