I would also like to know what your budget is, each of those companies offers a range of pre-builts for different budgets. That would be the first and foremost question you'd want to answer first along with what you'd be using it mainly for.
this choice... i can't find any PC made with this name, I can find a game console shop in India with that name.
Or a power ranger
and a Scottish Facebook page
none of it looks like a PC though
@Humayun if you want us to help, you need to give us more info along lines of questions asked by others above. Make a new thread with more info including actual models and a budget and your location, and we can help then.