It’s highly doubtful any jumbo lender will be able to do your loan due to your cumulative loan to value being over 100%. Most jumbo lenders require a minimum of 10% net equity, regardless of whether the second lienholder will subordinate their interest or not.
Well Jumbo Loans is certainly a good option as already you are having a good credit score and fitting in the criteria of loan. As for getting approval for such type of loan one must have good credit score, good amount of equity on the property, good income for making loan payments and adequate asset to cover disturbance in income. And for more certainty you can acquire quickquid for better progressive results and assistance for refinancing.