If you're seeking to hire someone, I recommend searching for someone with a strong selling background with presentation experience.

Presenting to an audience or client to me is a specific subset of public speaking. The ultimate goal should be communicating the value of your product or service to your audience.

I recommend using the "problem, solution, and benefits" framework. You can apply this to almost anything your trying to sell.

1. What problem does your product or service address
2. How does your product or service fix this problem
3. What benefits or value does the end user receive from this solution

As it relates to actual delivery, coaching and practice are the best routes to improvement.

May I ask what you believe your strengths and weaknesses are around public speaking?

The "important attributes" of any product are typically determined by your target market and vary significantly, but broadly speaking "ease of use" for the customer could be added to your list.

Partner with someone that you trust who has a business and start up background, preferably in the industry you want to start your company in.