Get the AI kit.
With the AI kit you get basically 2 nozzles, some silicone oil and something else? Everything you need for basic GBB maintenance AND filling it.
The madbull kit doesn't seal as well. You can fill it, but still need silicone oil. And it will take you so long to go through a can of propane.. honestly adding a drop there every 5-6 fills isn't much work AND you KNOW that you're doing it. What if the adapter failed, and you filled your gun for 100+ fills, ruined the seals and shit..
Iunno. I'd go for the AI kit in your situation, especially since you don't already have, or can readily get silicone oil that you know is ok for the gun.
Hope this helps!