Reddit mentions of Additional Digitizer Pen for L-Series

The N-Trig won't work. But the Samsung and these three will:

Wacom Bamboo Feel Stylus for Microsoft Surface Pro 1 and 2 and tablets with Feel technology https://www.amazon.com/dp/B00BVUQZZ2/ref=cm_sw_r_awd_o8yKub0T7FVYN

MOTION COMPUTING Additional Digitizer Pen for L-Series https://www.amazon.com/dp/B000A3YEQI/ref=cm_sw_r_awd_z9yKub09GZHAP

Fujitsu Digitizer Pen (1 replacement Stylus) T5000 https://www.amazon.com/dp/B00791UTH2/ref=cm_sw_r_awd_y-yKub0JTVMKF

I can tell you that anything that works with any Samsung Galaxy Note phone or tablet will work. Samsung did make a full-sized Note pen at one point (I have one, but don't see it currently listed on Amazon.)

Also, most old Tablet PC pens work. I use the pen from my Motion Computing tablet PC just fine, as well as this pen for Motion Computing designed to be more pen-like:

https://www.amazon.com/Additional-Digitizer-Pen-for-L-Series/dp/B000A3YEQI/

If you search for anything Motion Computing or Galaxy Note compatible, it should work fine. I have at least 8 styluses from various wacom-digitized devices I've used over the years (tablet PCs, Galaxy Notes, Asus EEE note, Entourage Edge dual book) and they all work on my Chromebook Pro.