I started back in the 1970s by shaving pastel sticks into powder and using them on armour( no dedicated powders back then). I've been using mostly Bragdons Powders in recent years and also tried some Humbrol powders which I found to be quite good also. A few weeks ago I tried some Pan Pastels which were excellent and less prone to fading if clearcoated. All these products seem to work well and do the job although they each seem to behave a little differently and some people seem to get along better with some products and some with other products. One thing I did notice is that Pan Pastels, in my opinion, seem to fade alot less than other products when overcoated with clearcoat.
If you can afford it ,try as many products as you can otherwise I would get what is most affordable for you and just master it.
Dullcote...I love the stuff but if you can't get it where you are try a spray-can of automotive matt out of a spraycan.