My research puts 141 programs between 15 and 20 for an average and 61 around 20 to 25 hours. It obviously has 100's of variables. Part 141 is typically lower in comparison to 61 for a couple reasons: you fly more regularly, the instructors are closely regulated by the institution, and the course is typically more structured.

My research was just calling various, about 20 different, schools mostly in the NJ area and some online research for a course I have been writing.

Finally, don't get discouraged if it takes you longer and if you are just stuck on landings go out and practice some of the maneuvers more, specifically slow flight. Don't sit in the pattern for 20 hours pounding landings, likely there is a deeper problem with basic control if you arrive at this bridge. Good luck.