Rayven, you sound hot as shit! I'm just guessing here, but I'm thinking that your PM box has been pretty full with volunteers, as well as come-ons...
Don't know your age, but someone who thinks a two-year relationship is pretty solid is likely just about 24... and fuck, that sure fits the bill for young, hot and solid...
Here's the thing. I really don't know a LOT about this business, but it's completely true that the girls are ALL in it for the money, so they'll pretty much do what you want. Fuck, these girls have to massage and be touched by some pretty slimy guys (no one on massageplanet.net, of course), so my guess is that NONE of them are going to be too put out by massaging a girl. That being said, "extras" may be harder to come by, and it may be hard for them to be truly turned on.
I'll PM you the name of one MPA who has mentioned to me fantasizing about being with a couple, but I'm not sure she was thinking about being all that active in the mix, if you know what I mean.
Also you might go for some of the smarter girls, who have been around a while and are relatively sexually open. Holly at Elm Street comes to mind (fuck, she ALWAYS comes to my mind), and she's rumoured to be bi - although who really believes anyone anymore.
Tarah and Lisa at HFH are also both pretty and smart, and my guess is that they would be able to ferret out the eroticism of the situation, whether or not it would have been their first choice.
The other obvious move is to ask Kayla through a PM - Paul's certainly active here, but he ain't a girl.