R&B Song Vocals / Feature

I'm looking for vocals for this song (demo attached) to release. If you're interested please let me know what your different rates would be for work for hire/credited feature etc. Thanks, George

Additional info:
Check out what I uploaded. The song will be released commercially. I'd like to use your name as the vocalist. I'm interested in hiring a pro who's worked on hit songs and have the budget for that. The lyrics and melody are already written. I just need a singer.. I'm an independent artist not affiliated with a record label. I need all the vocals recorded (lead vocals, harmonies, stacks, ad libs). I don't have a hard deadline for this.