For reagents, I would use nightshade, fleshfly larva, and either stinkhorn or emetic russula.
Edited to expand: since it seems like you're new to this, for making 3-effect potions/poisons, there are two general patterns. Most of the time, all 3 of your reagents will have to have 2 of the 3 effects you're looking for. Sometimes, you can have one reagent with all 3 effects, a second with 2 effects, and the last reagent with only one effect. In either case, you can never have an effect that opposes the effect you're looking for, so for example, you can never use Blessed Thistle (with a Restore Stamina effect) to make a Ravage Stamina potion or poison.

If you want to premake them for Normal and Master writs there is a pattern and a set list of required ones:

https://en.uesp.net/wiki/Online:Alchemist_Writ

https://en.uesp.net/wiki/Online:A_Masterful_Concoction