Dedicated Virtual Assistant

I would like a personal assistant who can do the following tasks:

1) Creating and formatting powerpoint presentations
2) Scheduling appointments
3) Basic proficiency in Microsoft Word, Excel and Powerpoint
4) Conducting web-based searches
5) Must be proficient in written communication skills in the English language
6) Helping with travel bookings
7) Organizing files and documents

* Available via email (mostly) and phone (only when necessary)
** Telephone interview will be conducted before hiring