I've ordered plants online a number of times and my favorite place to order by far is:
www.aquariumplants.com
I take them at their word that their plants come from "plant only" tanks and are "snail free". The plants arrive and they go directly into my tank(s), after I've pruned off any damaged or unsightly looking leaves. A few of the
Anubias I've ordered have come with some massively long root systems and I usually cut those back before securing them onto whatever it is I want them to grow on. HTH
PS. Limiting the light is something you wouldn't want to do. Plants require light to live and they've been shipped "in the dark". The sooner they receive light the better, IMHO.