From your question, it's not entirely clear what you're looking for. Are you looking for an existing story? Or are you asking someone to write one?

It sounds to me like you're looking for a story that would qualify as erotica (with some fairly specific elements) but correct me if I'm wrong. I'm not sure you'll really find what you're looking for here on this site. Certainly there are stories with erotic and/or sexual elements, but the general direction this site moves in, tends more towards stories about TG people living out their lives. There may be sexual elements to those stories, but those elements aren't the central theme.

However that's just my personal opinion, others may disagree.

This particular forum is aimed more at the nuts-and-bolts of writing and is generally frequented by those who write. It's a forum for talking about the writing process, looking for editors or beta readers, etc. Some people do offer ideas, but in my personal experience, what most writers lack are the time and the drive to follow through and actually produce. Most writers have lots of ideas of their own. There's certainly nothing wrong with asking for a writer though, and this would be the place to do that.

If you're looking for an existing story, you might want to take a look at some of the other sites that carry TG fiction.

Fictionmania would be a good place to look: http://www.fictionmania.tv/
The alt.sex.stories web archive would be good too: http://www.asstr.org/
In particular, the Nifty archive might offer some stories similar to what you're looking for: http://www.asstr.org/nifty/

All of those sites tend to carry more sexually charged fiction (if you will) and might offer you a better chance of finding what you're looking for.

And finally, if you can't find what you're looking for, you could always consider writing it yourself. That is at least part of why most of us who do write do it, because that's the best way to find exactly what we want.

Good luck in your search.