Alex,regardless of the loan you get you are not going to have much equity to draw on for a long time. This is true for two reasons, First you barely make a dent in your principal at all in the first several years of a mortgage. Second unless you find that one in a million house that is actually appreciating right now you will be upside down on the house faster than the ink dries on the loan documents. If you buy and you probably should not, I would suggest going with the loan that affects your cash flow the least that also does not leave you at risk of unpredictable trends in mortgage rates going forward. If you already have 10% down and the market keeps falling on the house you want, every day you have a higher percentage down! Why don’t you keep saving? Maybe you will have 20% down sooner than you think!At that point you could chose to put 5%-10% down if you want and won’t have to rely on the questionalble possibility of appreciation for your emergency fund.
Best wishes