I think most if not all guys are into TS girls are also into GG girls.  If they weren't they would probably see true male providers, although obviously the opposite is not true.  

My suggestion.... maybe reach out to some select clients that may like a** play or ones that are into some kinky stuff to see if they are interested.....

There are a few that advertise together, I believe Rachel will sometimes advertise with another GG, others are open to it, although it is rare.

Definate crossover-especially if she will do dom.   Probably my best session ever was with a gg and ts.  The ts was actually a surprise addition, but it was awesome.  I think if she found a solid partner, they would do great together.

Concur with both Gargoyle and Hittingcoach...believe here are plenty of guys into both TS and GG and would absolutely like to get both in the same room for a 3some.

I think that is a hot combination..

Why not give it a try? You would be hitting on two markets and it could only build up more interest rather than solo. Yes I do believe that many guys may like to try TS but would be on the fence, then they see your ad and say go for it...

I think it is great you are willing to be there for your friend. Says plenty about the person you are!!!  

I think this would be a huge idea.... and if you come to my area, let me know. I am more than willing to help. I am sure some of my regulars would be interested.