I’m curious if anyone would have a recommendation for lenders that offer second mortgages in Texas. I’m interested in a property that is listed at 300k with an assumable mortgage with a payoff of 220. Does anyone know...

If the other houses you own have no loans could you stack all their combined monthly rental income to pay off the remaining $120k mortgage before you retire? 

Talk to your loan servicer.

What asset category would you be securing your loan with? 

But also, you'd get a better rate just buying your home with a home owner loan. 

You can apply online and rarely speak to a person with a bank. 

Go to Etsy and search for "rental property tracker," and you will find hundreds of nice spreadsheets to track 10-20 rentals, usually for under $10.Software has extremely helpful features like online payments, marketing syndication (click a button, and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

Appreciation and cash flow make up part of the calculation of the Internal Rate of Return (also including depreciation benefit and amortization of the loan).  

Go to Etsy and search for "rental property tracker," and you will find hundreds of nice spreadsheets to track 10-20 rentals, usually for under $10.Software has extremely helpful features like online payments, marketing syndication (click a button, and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

When we underwrite a loan, we are underwriting the borrower.