Custom Login (Password lockdown activation)

Hello there,

I was wondering if anybody on here was able to help me find a suitable plugin for my wordpress project.

What I will need for the website is a complete lockdown on every page, so only authorized users can access pages. Along with this I will need users to be able to register, but the site admin has to confirm whether he wants them to have an account.

As an extra I would also like this to be done with ease-of-use as a priority due to an inexperienced user using the end-product.

Also along with this I would like to be able to customize the login page to make it look different.

Any help will be greatly appreciated.