My best pens with CI or stub nibs were all custom ground. I prefer to find a pen I like and then do what is necessary to get the type of nib I want. Pendleton Brown is amazing. He has customized nibs for half a dozen of my pens including TWSBs, Levenger Truewriters, and two vintage Esterbrook 9668s. Shawn Newton ground a really nice CI on a Kickstarter pen he made for me. Both Shawn and Pendleton were a joy to work with. The best CI nib I own, in use every day for almost a decade (except for an extended visit to Indy Pen Dance after a cat played with it*) is a Binder 0.9 mm Italifine on a Pelikan M800. The nice thing about the custom grinds was that they all came with a guarantee that they would be right or the nibmeisters would make them right. Most of the original manufacturer CI and stub nibs I bought required some tweaking to make them perfect for me.
Enjoy the journey on this one. These are some thoroughly enjoyable nibs to use.
*Pen left uncapped on desk for a few seconds while owner answered phone. Cat saw pen and decided it was a toy. Cats are proof that the earth is not flat because, if it was, cats would have knocked everything off it long ago. Linda did an amazing job repairing the nib. Yes, the cat is still with us. I bought her a Pilot Varsity of her very own which she ignores.