Realistically how many years would it take to achieve these powers?
It depends on how consistent you are with your meditations, but also on your past life advancement. Some people find it easier and are more natural to certain spiritual practices than others.
The more you meditate and open your mind, the clearer things will become for you. I remember when I first started meditating, I wanted to learn certain skills to "show off" to others (which would actually be a dangerous thing to do since high spiritual power can scare outsiders and can also put you in danger by other people in power who want to keep these powers hidden).
As I grew spiritually, I no longer felt the need to achieve these things, but I wanted to clear myself from past life karma, etc; I wanted to understand who I truly was and what I wanted in life.
Meditation is a life-long journey. You can (and should!) create goals that keep you motivated, but remember the end goal is the completion of Magnum Opus - immortality. Even if it doesn't happen in this lifetime, your progress will continue in the next life as well.
Many things will naturally happen the more you meditate (and you also do our Gods'power rituals in order to connect with them and to bless them). You'll feel energies more, become spiritually aware, you'll get a sensation of bliss and euphoria out of nowhere, you will increase your intuition and realize when someone is lying, etc. Many beautiful changes inside and outside.
As long as you keep on this path, many beautiful changes are going to happen.