You have a $500K investment portfolio and you want to purchase a home for your residence at a value of $700K. The lender requires 20% down payment. Should you make the minimum down payment or add more to it? Should you go for a 30 yr. mortgage or a 15 yr.? 

Look up current rates in your part of the world before you answer, and discuss the reasons for your choice. And, what if the lender could be persuaded to reduce the amount of down payment in exchange for 1/2 point increase in interest- would you take it? Why?