This is something I have wanted to do for quite some time, just never had the luck of being able to set it up...how would I go about doing this?  Find a GG escort and see if she is down?  Or is there any girls that offer this as somewhat of a regular thing that they do?  

I think it would be super hot, I'm in Los Angeles, any help would be much appreciated, thanks!!!

We get an ad about every 6 weeks on bp......A GG offering doubles with a TS and a TS offering doubles with a GG. Both are about 7's. I keep researching, but don't feel comfy enough to pull the trigger.
I would think in LA.....that option is readily available. I would start with the TS and ask if she could provide a GG double.

mr. mellow, in chicago we have two rare treats, t.s. rachel, and girlie girl audrey davis.  I have read a number of outstanding reviews on them, together, and I do know that they do travel alot.  do a little searching on them as individuals, and then bring it all together, along with a bottle of viagra and a pocket full of cash, but some things are just worth it.

Looks as though TS Rachel just left your area; Here's a thread on her:
http://www.theeroticreview.com/discussion_boards/viewmsg.asp?MessageID=56386&boardID=19&page=5

...and here's the review on the two together:
http://www.theeroticreview.com/reviews/show.asp?id=149746

I've also wanted to try this combo, the closest I've come was with a lady friend of mine in Thailand that was not only bi but had a thing for ladyboys also.

Sounds pretty amazing.  Expensive, but amazing.

I tried this a couple times and got ixed responses..
If your'e in L.A., go on the regional boards and put it out there. Don't worry about getting flamed or any of that hater shit.
There are a fair amount of GG providers who read the boards. You will propbably get respnses from them via PM. Just like you probably don't want any of your GG providers knowing you see TS's, the same goes for them not wanting their hobbyist friends knowing they want to see TS's either. B.S. I know.
There was a super Hot asian GG provider who e-mailed me showing interest. Her name is/was Marlene Amori. I tried to post her link just now but her profile has since been deleted. At that time I had already posed th queston with VO and it all looked like it might happen. I never could put the trip to La La Land together and it never came to be.I made the same inquiry in Phoenix and got 5 or 6 responses from verty nice, hot, well reviewed women there. I have found that there are more GG's hip to the idea than TS's, or at least based on responses via this site that's how it has gone.
I must admit that I haven't had the pleasure as of yet but it still sits at the top of my list as a Major Bucket list item.
Good luck,
R