Banks are hesitant to lend to prospective clients who have more than one property already.
A client of mine was in a very similar position to you, had a strong income, both current properties would have been rented out and covered by rent by 125%, yet they declined on the basis that he would have to be able to fund the repayments on the rented properties if they were to be vacant for a period of 6 months or greater at one time.
It's all going to hinge on your disposable income, the money you have left over after paying off all monthly financial commitments.
Have you considered location and price range for your new home in Dublin? If so, how much are you looking to borrow?
Another aspect that the banks will assess is your 'financial personality'. Generally, you have to be seen to be 'financially fit' - that is have a good track record of savings, a substanstial rainy day fund and for you not to be in any way reliant on credit cards, or short term borrowings to fund monthly excesses.
You have a strong joint income, and provided you match the above profile, you have a better chance than most.
Best of luck!
J