Which calculator would you reccomend?

[Logan]

I don't know that any of those calculators would be useful for Calculus, where the focus is more on the process than on a numerical answer or estimation.

But for a daily calculator, out of those, I'd definitely recommend the 42s. Or if the Prime is really banned, you might consider a 50g which can be had for as little as $50 and could be handy for verifying exact expressions in Calculus.