I think Lindstrom, Demidov and Celebrini will be gone in any scenario barring a lottery win.
Catton may be available if the Flames get the 8th pick.
But more likely, the Flames pick around 10th and those guys will be gone. For forwards, Eiserman and Helenius may be in that range. Most have Iginla in the
early-to-mid-teens, but the Flames will surely consider him.
Parekh, Buium, and Yakemchuk would be the defense to look at (most sources have Silayev, Levshunov and Dickinson going earlier, but anything is possible).
So I think the five most likely to be available and closely considered in the Flames' range are Eiserman, Buium, Parekh, Helenius and Yakemchuk. And Iginla of course, though they if are set on him, they could consider a trade down... But the whole ~4 to ~18 range will be full of volatility. Anything can happen.
Personally, I would ecstatic if the Flames snagged Catton or Buium. One leads the eligible CHL draft eligible players in points, and the other has the best defensive NCAA productions in generations. And I'm a sucker for point totals (empirical results). I think if the Flames pick a defenseman, it will be hard to miss - because they're all good (though I'm not a huge fan of Jiricek). All of them have possible top pairing upside IMO. But very few players have #1 center upside.