Can i ask to purchase a home on land contract?

there's a home that i'm interested in that is for sale by owner and has been that way for approx 4 months. the home is currently vacant. is it rude to ask to purchase the home on a land contract rather than going through banking channels? i'm pretty sure, due to the digging i did online, that the owner passed away in october and left it to his children (scary what you can find online in a short amount of time). i just don't want to insult them. mine and my husbands credit is ruined beyond repair and have to file bankruptcy. we would like to be able to offer them a balloon payment as soon as possible, possible after 5 or 7 years. realistically, i'd like to lease with the option to buy for 5 - 7 years and then get a loan after the dust has settled for us. i don't know how to lead into this conversation.