I would definitely mention the fact that you are under contract.  I can't see any harm in it and it will probably look like a measure of good faith and honesty to Google that you are telling them everything.

Good responses.  Here is what I would do if I were in your shoes.

I would start off with a humble sentence: "Hi Google team.  Thank you for receiving my reconsideration request.  I realize that some of my links were not in line with the Google Quality Guidelines.  In this document I have outlined what I have done to rectify that."

Then, I would list my links.  So I'd say, for example,

"There are 10,000 links that come from example1.com.  These were links that I previously paid for.  I now realize that this is against the quality guidelines and I have had those links removed (or nofollowed)."

I'd do the same thing for all of my bad links.

If I had any where I couldn't get the links removed or nofollowed I would say this:

"There are xxxx links from example2.com.  I have contacted the webmaster by sending an email to **admin@example1.com.  **Here is a copy of my email:....

...I also found this email in the WHOIS data for the site and sent an email which you can see here....

...I heard no response, so I used a contact form on the site and have yet to hear back from them.  "

I would make sure that I had an explanation for every single link pointing to my site.  I wouldn't try to hide anything.

I would end with something like this,

"Thanks again for considering my request.  From this point on I am committed to following the Quality Guidelines."

In the past it would take ages to get a response (and some webmasters never did) but Google has upgraded their response time.  Most requests now get a response within 3-14 days.

Good luck!

I have a story as well about something that happened to me today and it is relevant to your question.  We have a real estate site and today we started getting hits for "top realtor in [city]".  I was trying to figure out why because we haven't optimized for this at all.

Well, it turns out that I recently wrote a silly blog post called "Top 5 videos about....", and I also had a post on our site called "Top 10 neighborhoods in [city]".  The fact that the keyword "top" and the keyword "realtors" and the keyword "[city]" were on our site actually makes us rank on the first page for "top realtors in [city]".

The more content you have on your site the better!  As a result of this discovery today I actually rewrote our home page to include more keyword phrases that I want to rank for.  (You have to be careful to write for readers and not just search engines though.)