Hmm Kashif, Is this the first time you are investing.. i know its quite difficult to take a call... well there are many factor that decide and one of them is the availability of fund. if you do give in 20% of the amount , it is a considerable drain on your savings and might not be able to diversify your investments.... so think , take time and then decide
yea..sandhya is quite right , but then most banks prefer customers who are willing to pay more down payments and if you do then you just might get a better interest rate and the process of disbursement of funds too is faster.
Another advantage of more down payment is lesser monthly payouts as you get lesser EMI. so you will have higher cash in hand monthly that you can use to secure your investments .