Interstitial pages mod for Drupal

Hi we are a UK charity in need of an interstitial pages mod for Drupal with the following features:

Ability to define number of clicks before Interstitial is shown.
Page to Interstitial when click count is hit
Check box for outbound links (True/ False)
A way to override Interstitial trigger for certain node types, like Blog or Index for instance.

How we would like it to work:
Ideally I want to create a Page with the survey embedded via iframe then in the Interstitial mod link to that page, set how many clicks before it triggers and if all out bound links should always Interstitial and an option to not Interstitial clicks from certain pages, never Interstitial from a home page click for instance.

Please provide your hourly rate (remember we are a charity) and estimated time to test and deliver the mod to our servers.

All the best

John