Billybob: Good question. You'll want to stick with the basic stretch and the JAI stretch for the first 5 weeks. The other stretches are more intense, and jumping right in with them can cause several problems.
For one, it can lead to overtraining if you go overboard. For two, it might actually stop you from gaining (believe it or not, less is more in the beginning!). For three, it makes it harder to increase the intensity as time goes on since you are already starting out with advanced exercises.
Check out the table at the bottom of this page to see when you should start implementing advanced stretches:
The Penis Enlargement Gym - Advanced Exercises
If your focus is mainly length, do a light tug after each jelq and focus on jelqing with a low erection level.
Hope this helps,
rem