Open Cart Project

Based on our current e-shop build on open cart- platforn
I need to have "pre-order" feature to add on, which is a module we currently do not have in our Opencart (ver.1.5.5.1) admin panel.

The requests of this add-on program are as followings:

1) for a customer to be able to select a larger quantity of a product than is available (especially when some items are with 0 stock quantity but available for pre-order)

2) for the customer to be able to go through to checkout and purchase (process full payment) the quantity that he/she desires

3) for the customer to then receive an email telling him/her that they will receive another email, once the additional products are available, as well as shipping information etc. (these emails designs are also included in this project and would be automatically sent out by the website also easily customized for administrators from admin panel of Opencart)

4) Add extra feature at the checkout/register, asking where you heard from us.

Google/Friends/bing etc...

We are looking for experienced open cart developer for our on going project.