Invitation for a client

Hi kindly correct my grammar, i want to invite my client over lunch or dinner with her family, below is my constructed message:

Ms. Cecilie, I have already requested with my manager to extend the unit holding for your unit 9KL, and it was granted and extended until wednesday november 13,2013. Also, I would like to invite you over lunch or dinner on wednesday, Cyma Restaurant at Robinsons Magnolia Mall, this is to entertain any technical concerns with you and your family regarding on the project, don't worry, for it is all my treat. Shall you be available on wednesday lunch or dinner time, please let me know so I can make an advance reservation for us.