You have nothing to worry about, ~80°C is not a dangerous temp, however, is not an optimal temp... (especially if the dust starts to accumulate on the heatsink).
An aftermarket cooler is always better than the Intel heatsink, no matter what, just pick a good (cheap) & silent aftermarket cooler.
The temperature difference between the games and video editing is normal, because in video editing the CPU have all cores fully loaded, and most importantly, because is using the pipeline AVX 2.0 of the Haswell architecture (plus in this situation there is a small Vcore boost in adaptive mode). Therefore, it is normal that the CPU generate much more heat and reaches almost 80~90°C on stock Intel heatsink.
Choose any "tower" model that you like, with 92mm or better 120mm fan, obviously looks at the measures and if it fits in your case. some examples; Hyper TX3 EVO (one of the smaller towers around, good compromise between heatsink size and performance), Hyper 212 EVO (much bigger) etc.