Dear …
I will be in the __(location)__ area next week and would like to have the opportunity to meet with you. It’s been such a long time since we’ve had a chance to sit down and talk. It would a perfect time to be able share some thoughts with you that I had on __(name topic)__.
If it fits into your schedule, I’d like to treat you to lunch sometime between __(date)__ and __(date)__. If this works for you, please let me know so we can set something up.
I look forward to hearing from soon.
Sincerely,