First of all, thank you so much for your explanation. I'm newbie in vaping, and I just realized the difference between the two ohm meter. I think I will just use prebuilt wire for the beginning, therefore I don't really need the complete toolkit. I will save some more money to buy the coil master kit you recommended.
My local vape store sell it for around £23 btw.
One more question please. For newbie who want to use prebuilt wire, do you think I should buy the alien kit, or just the alien mod and buy another tank? I'm considering to buy Medusa RDTA or Avocado 24 from GeekVape if I buy the mod only. My consideration is it will be cheaper, since the alien kit doesn't include the RBA, which my local vape store sell for £8.