Chase, I believe you'll want to make sure basic troops are stocked (Nurglings, Plaguebearers, Daemonettes, Bloodletters, Pink Horrors). I'd also stock a couple of each Greater Daemon, plus Daemon Princes.
Have at least one of each named character/Herald, if not two.
Yeah, you'll have to hedge your bets I think. The new stuff, who knows? But players, especially new Daemon players, will need the basics to start.