AdWords Conversion Tracking Confusion

Through EditFast.com and my 2,000 freelance editors, I provide editing, proofreading, and writing services. I am familiar with AdWords and I want to start several campaigns, but I want to get all my ducks in a row first. One of the issues I am having difficulty with is conversion tracking since we deal with clients in several different ways, that is, there are several ways for the client to submit a document for editing depending on a variety of factors (type of document, type of editing required, how they want it edited (let EditFast take care of it, choose their own editor)), so my question is, how do I track these conversions from the click on the ad to the acceptance of the editor's estimate? I have a feeling it will take a major renovation of the site to achieve this, which is not something I wanted to do right now. The problem is that once the client comes to the site via an ad, they are then able to 1) contact an editor from the editor's web page profile, 2) search for editors from within the client area and request estimates from several editors if they wish, 3) send it directly to EditFast.

Should I consider the submission of a document a conversion? I think not, because it will still depend on the client's acceptance of the estimate, which quite often is not accepted for various reasons that may or may not have to do with the ability of the ad to attract willing "clients."

The acceptance of the estimate seems to be the place to claim a conversion, but how would I track the client through that process as it is several steps and maybe even a secure login away from clicking on the link to accept the estimate aside from the fact that it may be days later that they accept the estimate. Advice and comments are welcome.