rocknguyen my reasoning is as follows.
The OP requested a degree of future proofing, hence the suggestion of an i5 processor. Links to graphics and multimedia are increasingly included in office presentations, so having a multicore processor is an advantage. I agree that an i3 processor could handle today's computing demands. Here in the UK, there isn't that much of a price differential between the two processors once incorporated into a complete system. So the recommendation is to go with something that is a bit more powerful than is technically needed to satisfy the basic requirement.