It's not a matter of us telling you what to buy next, but more of the matter of what do you need to meet your journey in smoking meats.
If you truly like smoking meats and wish to pursue the more advanced aspects like curing meats, making sausage, and smoking hams and / or turkeys then I would suggest you consider investing in a good smoker that can last you a lifetime.
There are so many things to consider, the type of fuel you wish to use, the capacity of the cooker, reverse flow, adaptability to controls, and many other options.
Think about your need, and then consider your wants... Somewhere in between lies your own answers.
Humphrey's DownEast Beast W/BBQ Guru