Sounds like you may want to explore "subject-to". That is, taking title to the properties subject to the existing financing. That way, you pay the lender(s) directly without getting new financing.
You'll get a lot of static about "due on sale". However, lenders typically don't call a loan when the payments are consistently current - they sometimes do, but not as a rule and not usually unless they have a reason for it.
One way around "due on sale" is to combine subject-to with a sandwich lease option. In a nutshell, the current owner keeps title instead of deeding the property(-ies) to you - that defeats "due on sale", and gives you a lease-option with the option to sub-lease.
Just some thoughts ...
thanks! This helps!