[morzh]

Hi temp means 105 C and most capacitors are 105C. Some are 85C which (I think) is sufficient. Your ambient is not going to be 85C.
I doubt many of us with discern distortion induced by power ripple if it is small, and ESR does contribute to it (in fact it causes part of it). Your ESR is not that important when the ripple is the one caused by the fact that the cap is charged and discharged by rectified waves/constant load, as you could make the cap sufficiently large to have almost no change in V, but when you draw current your ESR times your current creates the ripple ad this ripple will be the same shape as your load's voltage and will cause distortions.

By buyng a large cap you almost automatically will take care of all of this.