I drew these guys with a Pilot Custom 823 FA and Platinum Carbon Black ink. The FA nib has a good drawing width on watercolor paper - one of my favorites. It's a soft nib but I don't use the line variation, just some nice shock absorption with each downstroke. The Carbon Black ink is out-of-this-world good, though being pigmented I fear keeping it in too many pens.
My current sketchbook is the lovingly titled "Blue Sketchbook." Feel free to enjoy its many, many pages, plus two bonus zoom-ins of favorite spreads! Let me know if you have any questions.
I'm not good with lettering, but it is what it is :) Was interesting to know that Peace lily is not so peaceful... If you have pets and children, you need to be careful with this flower!