I love my Annabelles and think they'd look gorgeous around the front porch. I planted a row of 5 spacing them 3' apart on centers and they form a full solid row now in their 3rd growing season. They were almost full in their 2nd year, but you could still make out individual mounds. I've read in a few places that Incrediballs don't live up to their hype about never drooping, I have no experience with them myself though, but either one would look and do beautifully there. I would think if you call around you'll be able to find Incrediballs near you, I see them around Chicago and suburbs.
I agree with trying to get whatever one you decide on locally. You'll start out with much healthier and bigger plants than ordering online, and you can pick out well-rounded ones instead of lopsided growth you might get from an online order.
You definitely will not need to water twice a day, not even once a day. The first fall I planted mine I'd have to water maybe every 5-7 days, I'd test the moisture at about 3" down with a water meter, continued that until the hoses had to be put away. If you decide to plant them now, would probably need watering more often, but still not daily. Make sure you water long enough to get down deep, not just a surface watering. After that first fall I've never had to water them again. Maybe if you're weeks without rain in July and August they'd need water, but Annabelles are really very maintenance-free.
