Real Estate Mortgage Loan Refinacing

I bought a house 6 months ago before I sold my condo. I borrowed the money from my brother for the new home until the condo sold. I have a written contract and have been paying interest. He is starting to get nervous, so I would like to take out a mortgage for the home to pay him back. Would this be a refinance or a home equity loan? Also, when the condo sells, I expect to still have a mortgage of about $40,000. Assuming I take out a new mortgage now on the house, when I pay 3/4ths of the loan amount off in one lump sum, will my monthly payments decrease or will the monthly payment amount stay the same, but the loan be paid off more quickly?