Is your Roth maxed? You can take contributions later with no penalty whilst still letting the growth keep growing. Can't catch up on ira contributions like you can college saving.
That and the Utah 529, that's what most guys around here have, I believe.
Doesn't really matter. The amount that you contribute is more important than the plan. Pick one and put it in the target date fund based on the year they're gonna start school.
Utah and Nevada have been good for awhile but a number of states have stepped up their game in recent years and now offer low cost index funds. CA, NY, MA, MI, IL are all pretty good now. Some will offer higher fee managed funds as an option but also include low cost index funds.