Welcome Tin, here's something that I would do given your budget and desire for a satisfying HT. I would definately look at the M22's for your fronts as John and Dakkon suggested, but what I'd do (I stress "I") is go with the QS8's over the 4's on the surround side and in order to stay within budget, for now, I'd forego the centre and run a phantom centre for the time being...this will be about in line with your budget and these speakers are certainly an upgrade over the others for the space you are filling and you won't have the "what if?" hee-bee-gee-bees later on. To bring the cost down a little(10%) consider the Factory Outlet...nothing wrong sonically, barely visible blemish if you can find any.

Half of communication is listening. You can't listen with your mouth.