It sounds like you are seeking a loan of $500K with a 20% interest to be repaid over a 5 year period - payments to start in year 2.
If so - then your annual payments would be $159,000.
You should be able to get a loan for less than 20% interest.
If you are looking for an equity investor, you`ll probably have to show them a better than 20% per year return.
I`m not wanting to be harsh - but you do need to be clear about what kind of capital you are seeking and what kind of deal you are willing to offer.
Business Growth Masters, LLC -
Capital Catalysts for Entrepreneurs
Home of the Scalable Business Plan and QuikStart Capital Programs