In regard to the ballast resistor, the one that came with the kit will work fine.
There are a lot of really smart people on this website (not me) that have figured out how to optimize every detail for maximum performance on a great variety of things. This often leads to very detailed and specific advice. And it is usually good advice.
However, if you are just a run of the mill normal schmuck like me, you often just want to get your car running reasonably well so you can drive it. In this case some of the advice can be over the top for what you are working on, and may not be worth the extra effort or cost.
You kind of have to figure out for your self how far down any given rabbit hole you want to go. Unless you are a racer looking for every last horsepower, the point of diminishing returns happens often pretty early.
One of my friends used to say: poor people have poor ways….