It's pretty hard to find a lineart brush that you like, but this has helped me tremendously with my lineart, and I hope that it will help you too.
An example of how smooth the lines are.^
For better and straighter lines, adjust the stablilization. You can also change the thickness, opacity, anti-aliasing, and the taper settings. So, you can adjust the pen to your liking.
Happy drawing! ^-^