Stevia is one of the reasons I never even considered doing something like the Whole 30. Well, that and the no-caffeine bit, which goes hand-in-hand with the stevia.
My favorite is New Roots stevia extract powder, which has no fillers. A 30g container costs about $12 and it lasts me months. A little bit goes a long way. Not sure if it's available in the US.
I've tried Truvia and others with fillers/bulking agents like chicory, malto, along with xylitol and erythritol etc and just plain don't like them.
Also don't like the drops at all. Did use most of a tin of Sweet Leaf tablets last summer, both when touring and camping on my motorcycle and while on a work trip in the UK for a month.
Not nearly as good as the New Roots IMHO, but handier when on the road, and there was no fine white powder with a bitter taste to try to explain when crossing borders.