"sure do have" is correct and usable in written English.
This phrase is generally used to express agreement or affirmation. For example: "Do you think we should go out for dinner tonight?" "Sure do have!".
McDonald's sure do have confidence in their branding.
Man, those Asians sure do have funny-looking eyes!
"You sure do have a lot of friends," she said.
Watch out: a few more steps and you'll find yourself saying they sure do have rhythm.
But we sure do have some nice views of the Golden Gate and the surrounding hills.
"We sure do have a nice-looking team," observed Peachie Brown, one of the softball wives.
I sure do, having dusted off a number of Civil War analogies for future columns.
"I sure did have a chuckle.
People would say, 'There go the crazy Americans.' We sure did have a lot of fun.
Gail: I don't know if Ann Romney is smarter than her husband, but she sure does have the corner on Romney social skills.
Princeton = Service – I originally stumbled into this as a joke on the STEM folks, but it sure does have clarity; it's hard to misinterpret a one-word strategy.
