Hi Jim: Thanks for your questions. I think what you’re referring to is a 1031 exchange where you defer capital gains taxes by selling one property and purchasing another one that is similar. It’s a good idea to consult with a real estate tax expert or CPA for the specifics on this. Here’s an article on 1031 exchanges. https://fitsmallbusiness.com/1031-exchange-like-kind/
In regards to investment property loans, different lenders require different down payments depending on the type of loan, short term, interest only etc, and other factors like your credit score, the property you’re buying and your flipping experience. Here’s a hard money lender with lenders listed in every state.
Hope this helps!
Best of luck,