What gear should I be targeting as a Druid approaching lvl 40?

[Bugsley]

I have just been trying to get any WIS pieces I can as I'm leveling, but I wanted to know if there are items that are integral to Druid solo leveling later on that I should try and buy.

I have seen luminescent staff mentioned before in other threads, is that worth a buy for the free lightning strike? Any other must-buy recommendations? I pretty much play solo always, for what it's worth.