I will be visiting on Tuesday the 23 of July. I have a disabled husban who needs a motorised cart/chair and a wheel chair for my 79 yo Mother. Is it hard to rent those at the park. Any way to reserve them?

You can rent them at the information center. It only takes a few minutes. The park has a nicely thought out 10 page document on their website all about accessibility. If you go to the website and scroll to the bottom, you will find it in a blue section under "park information". It tells all about how the park has planned for people with mobility issues.

Yes and the Information desk is happy to help you