What should I add?

Hello! I just started 40k - I have 4-5 battles under my belt and I’m enjoying it. The games I’ve played have all been with Salamanders. But….i just got a line on getting some really cheap/free Tyranid models.

Do I need a second faction? No, but who cares!

The models I can get my CA coated fingers on are:

Hormagants
Tyranid Prime
Neurolictor
Hive Tyrant
Norn Emmisary
Tyrannofex

While I’m certain I will own more than I need, for now - what models would be good additions to get me to a playable Tyranid list?