Consult a local CPA or even better a tax attorney.
Paying someone for their time never has and never will be illegal. Being an escort is not illegal. Being a prostitute is. If you really want to run a completely legit escort agency, you may even want to consult with the local police and/or DA's office. Also a very good criminal defense attorney could be a big help at how to avoid needing their services.
As has been said, do NOT barter for these services. Paying a true professional is the best way to get the best service