To be honest, no female escort I know would be interested in meeting up for a 'getting to know you session' to see if you gel, without being paid for her time. Definately not on the basis of 'maybe this will lead to a booking'.
I agree with the booking advice above, and I would add that it's probably best to wait until you have an actual booking request, so the escort you approach doesn't think you are a time waster . Believe it or not I get so many guys emailing me with similar enquiries that are not genuine.
I am sure the escort you book, when the situation arises, will be experienced in this type of thing and will be professional and make sure the client has a good time, regardless of whether you and her are bff's, because cash is the incentive here, remember!