Roster for MShep: EDI, Dr Chakwas, Samara, Kasumi, Kelly Chambers, Khalisa, Diana Allers, Dr. Michel, Shiala, Aria, and Maya Brooks Roster for FShep: EDI, Vega, Samara, Zaeed, Kelly Chambers, Feron, Joker, Javik, Aria, Shiala, Grunt, and Anderson.
I think this would be super cool! The only thing I'd say, and I know it means a lot of work for you, is making some of the options available to male and female Shep. I'm still bitter over Femshep not being able to romance Jack, Tali, Ash or Miranda (especially Tali, since they recorded the romance dialogue and everything!).
Character ideas! Aria, EDI, Dr Michel, Kirrahe, Kasumi, Hackett, Anderson. TIM, Maya Brookes n Kai Leng if you want to offer ~forbidden romance options.
You could also do romances that weren't offered fully, like Kelly Chambers, Samara, Vega, Javik, Allers.
And if there's anything I can help with along the way (providing models, dialogue, testing or anything else you can think of) I'll be happy to help.