Hi, I think it is better to deal a fixed price for a total product. You can pay 50% when the first version is completed, then, after fix and improve it, and when you be satisfied, you will release other 50%. I am sure I can develop a great presentation for you. Only need your main ideas, preferred colors and a company logo and start working.
I can manage charts, bars from excel sheets data.
Please contact to have a deal about price depending of the size of presentation.