Re: Advice on new build
Aye, to build on the above, if you're a heavy user of Premiere, then you'll benefit from a dedicated graphics card. As far as I know, Nvidias "CUDA" technology is still superior when it comes to that piece of software (I'm not too out of date I think), so if it fits your budget, adding an Nvidia GTX1060 or something like that will improve video rendering speeds. If you're only a light user then no real need though.
8GB of RAM and i5 6500 seems to be the standard for a performance machine these days, 250GB (or more) SSD (Samsung EVO or similar) for your OS with a larger mechanical HDD alongside (1 or 2TB is probably a good shout) and a decent PSU.
If you want to use it as a media machine as well, then it might be worth fitting a Blu-Ray drive, but a lot of items are downloaded these days so that is probably surplus to requirements. I would fit at the minimum a DVD drive though for legacy purposes.
Athlon II x4 645 || 1TB 7200rpm HDD || EVGA GTX 650Ti OC || 8GB DDR3 RAM || Windows 7 Home x64
i5 4210M || 500GB Samsung EVO 850 SSD || GeForce 825M || 16GB DDR3 RAM || Windows 10 x64