Check out HandyControl, it allows you to do many things with your handy like control it with your controller, give a live chart preview, change the stroke length, apply rates (make the chart faster or slower), add stroke jitter, and a bunch more, here is the link:
https://discuss.eroscripts.com/t/94
Also in the same folder where you download the app is some files, these are about ten minutes each and are made for endurance as they get progressively harder. Great for stamina training (since you said you wanted files you can get used to)
Once you want to see what our community has charted you can check the Free Scripts section. Keep in mind since the great #pornhub purge just happened, your options are limited to ones with direct downloads or links to other streaming sites (and even less if you aren’t into IRL), since we are still a small community
Welcome to Groove Coaster the interactive world. Enjoy your stay.