Can I purchase hardwares on my own instead of renting?

Yes. You can find those products in online shops and vendors.

1. Label Printer - Brother QL820NW
   http://www.brother.com.hk/eshop/zh/ql/5558-ql820nwb.html
   
   
2. Pocket WIFI 
   
   
3. Sim card with internet data
4. Mini iPad or iPad - Apple Stores
   https://www.apple.com/hk/en/ipad/
   
   
5. Label Rolls - Our default model is: DK22205
   http://www.brother.com.hk/eshop/en/continuous-length-tape/672-dk22205.html