I have been using Projector and Tv's for almost two years directly on the main power. I haven't faced issues till now. There is also a MCB switch which has never tripped so I assume that there is a stable power in my area.Going by your list of equipments I dont think you need a UPS at all, none of them really care for a graceful shutdown. You could look at fast acting relays which can prevent high voltage damaging your equipment. I remember seeing one in one of the FM HT setup. Else, typically your regular MCB does the job, but its sometimes too slow to prevent damage. Again, this is only if you are in typically bad power area with lot of fluctuations.