Thank you for your suggestions, from that I've understoof that 500 Watt PSU will be good for my rig. (Correct me if I'm wrong)
On the contrary, I took a look at your suggested UPS as well, but it seems a bit expensive to fit in my budget. You also said, that UPS would even give power to your TV. Though, I'll be highly obligated if you give me some more suggestions of cheap UPS's which is just fit for my rig at the lowest price.