unlikely to get a mortgage, you want total borrowings of 250+120k = €370k on a combined salary of €60, 6 times multipla, and with the negative equity in your BTL,
how much are you paying back to PTSB and what could yo afford to pay on the new loan, they would probably only allow 30-35% of net income to service loans, and Rental (after tax) would only cover the tracker interest,
Interest on new loan, likely to be circ 3-4%, so for a 20 year term, to clear both loans, you are looking at €1500 for just the capital element, and then the interest would be circ €800 between the two, so net €2800 per month, which even taking off the rent, is stil la significant amount of your gross, let alone your net salary