M.K.
There's one called Potty Time for Boys (also available for girls) that my kids liked because of the flushing toilet sound button. Very basic and illustrated with a toilet rather than a potty chair. Also it's a board book.
If you show videos, Go Potty Go and Potty Power are both hits with my children with songs about using the potty, saying goodbye to diapers, and washing your hand. Yesterday my five year old wanted to watch Go Potty Go and then he and his 3 year old sister marched around singing "I'm Proud to Wear my Underwear"
As a side note, 19 mos is still on the young side: I hope you can harness his enthusiasm and train him early, but don't be surprised if his interest really wanes and resistence rears its ugly head! Good Luck!