Which hook type should I buy

I normally use a curve hook on my kd rig which as the name suggests has a gentle curve along the shank. I believe these hooks provide an excellent hook hold due to the shape. I find these hooks actually curve into the carps mouth, meaning to remove them they need to be curved out again which is why I really like this type of hook. They also naturally turn in the palm of your hand again due to the shape which is exactly what you want when trying to hook a carp. An alternative to this is the wide gap hook, where the space bewteen the hook point and eye is much wider. I tend to add some plastic tube over the eye to make the hook turn more aggresively. 

When I am fishing with a chod rig I will use a chod hook where the eye is turned outwards. This is to ensure the hook is in prime position when sitting under the pop up boilie. The nature of the chod rig really does mean you must have this type of hook in order for the rig to function as designed. 

For more info check out this link: https://www.anglingtimes.co.uk/advice/tackle/articles/guide-to-carp-hooks