Hmm… the actual truth is that iPad can never serve as a laptop at least for now, not even the Chrome Tablet cos they have limited storage capacity, when you run out of storage space you will be forced to get an external drive. Also, since you will be typing and preparing PowerPoint presentations you sure need the keyboard and mouse.
So I will advise you to go for ultra-slim laptops or hp Pro books instead of iPad or Tablet.
For convenience, yes iPad has it, but can not actually serve the purpose of day to day office work, and also your device needs to have an HDMI port so you can connect to projectors.
iPad is better used for video conferencing, face chat, surfing, and responding to emails.
For your type of day to day work, you will need the keyboard, mouse, HDMI port and probably need to install some applications like article writers or spinners. Only laptops or Detachable Laptops and pro books will give you these functionalities in one.