Which DJ Mixer should i buy?

I was a mobil DJ for 25 years. When I started NUmark was the brand. Things have changed since. If you are working in the UK marked why not go to a radio station or club and see what kind of set up they have. It will also depend on what type of DJ you want to be. Most people use computer programs which is dangerous because if the program fails you better be able to sing good for 4 hours or so. Do a search on PC for dj equipment too. This will give you an idea. The best investment though is SPEAKERS. If you don't have good speakers then your other equipment won't mean anything. So you could use a cheap mixer and get away with it if you have good sound. I wish you the best. And start out doing parties for folks your age. Mix up the music good and try to put the same segway together, the mix of the same beat too will help you with your gigs.