@kingpp The first thing I will say to lower your expectation. Birds will build a unique relationship with you and you simply can't know how it will turn out.
Now with that in mind I will share my insanely sweet and wonderful plumhead experience with you.
Quick summary on touch: Plumheads, and other asiatic or psittacula parrots, do not allopreen. This means that they don't groom each other's head except in rare situations. Head and body touch isn't a common behaviour, except when copulating with their mate. Sometimes humans assume that all parrots like head scritches and they try and develop this head touch bond with their plumhead. The plumhead may accept this touch when it is a baby, but as the bird matures the touch is very confusing to the plumhead.
I got my plumhead understanding that I would never pet his adorable fluffy head. This was ok by me! I never reach toward his head and I always approach him moving my hand from below his feet up to his feet, not from above him swooping down..if that makes sense. This method seems to have worked very well as now my little guy is very comfortable around me and he hops all over me. We have developed a very trusting relationship and he follows me everywhere. What I have found very interesting is how little touch matters. Even though he doesn't "cuddle" he is strongly bonded to me. When he first came home it took him several days to feel comfortable in his new cage, several weeks before he started making any vocalisations. I never tried to get him from his cage when he was new to my home. I have a cage with a top play area and I would open his door and leave him to it. One day he hopped on my shoulder and it was really exciting. I remained calm and talked to him a little bit and from there our relationship took off.
Plumheads do require a diet with ample fresh fruits, veggies and even flowers/blossoms. So do keep that in mind. It isn't a once a week treat, it is an everyday diet. I probably spend somewhere around 30$ australian on his fruits and veggies weekly. Sometimes more or less depending on season. 1 package of edible flowers costs around $8 just to give you some idea.
Plumheads are very social and he gets along with all my other birds. However he can be a little jealous if the other birds stand on me ..but he pinches me for it.. go figure. He is also very smart. Tricks are a breeze and he picks up concepts quickly.
He flies around my house, the high energy and want to fly, I think it is impossible to have a happy plumhead with clipped wings. He flies laps around the house, multiples in a row. He will work himself hard and perch next to me panting from the effort. He loves flying. He chooses to do it.
When he was a baby he would test everything with his beak. He would pinch my skin a lot, because he found it to be just weird and interesting. So I had very sore hands for a long time. I started carrying around parrot foot toys and I would hand him one when I picked him up. This has since passed and he never pinches now, that is unless he is jealous I am not giving him all my attention.
This is in no way fully inclusive about my experience, but I hope it gives you some ideas. Plumheads rock! -- oh yeah and they can be noisy sometimes, like any bird, so don't believe the websites that say they are quiet. He can be very chirpy and I love him when he is because he is a happy little guy <3