Need some coding insights for web application

Guys, I need some programming tips for a project I am working on...

I am developing a web application where the user will fill up a form with items to buy and send the "price quote" to all vendors he wants. The vendors will also have an account to on my system and will view customers price quote and reply with items prices.

The whole system is very similar to any freelance website where the employer post a job and freelances apply to the job sending cover letter and answering questions, etc.

My question is, how can I do it ? Is there any similiar codeigniter project where I can look at it ?


I can provide you more information if you need. I just need some insights to get start codeing....

Thanks

anybody ?