Starting Oct. 1, more than 1 million uninsured Kansans and Missourians will, for the first time, have full access to a computer-based health insurance marketplace at www.healthcare.gov. There they can see and compare qualified health plans and prices and perhaps obtain tax credits to pay for the coverage the law says almost all Americans must have by the end of the year. It's a critical part of the Affordable Care Act. It sounds simple enough. But local experts are nervous. The enrollment process, they say, will present the uninsured with a complicated blizzard of choices that can befuddle even those who have had insurance for years.