advice needed for the build

[thjbd]

Hi, I am from Bangladesh. Sorry for the low res picture below
This is my old pc. i am planning to change everything inside of it except case.

This is the pc i want to build for web development mainly. Mainly i will use Linux here. I may play some games as well. http://pcpartpicker.com/p/gynQLk
for your convenience, i am pasting the specification here:

• 
  processor Intel Core i5-4590
  motherboard Asus H97M-E
  Ram 8GBx1 Gskill (F3-1600C11S-8GNT) or Corsair 8GBx1
  HDD Toshiba or WD 2 TB [toshiba is cheaper here]
  PSU Corsair 450VS [Not 450VX as seen on pcpartpicker, it is not listed there]
  UPS APC or apollo [whatever cheap i can find cause i will buy an Instant Power Supply in future]

IF i can't find the PSU at the time of buying, i may either one of these
Thermaltake 530W smart
cooler master GX II 450w

Now my question is
1. will Corsair 450vs PSU work with Asus H97 M-E mobo?
2. in future i may add an amd R7 260x like GPU. will it work with the PSU?
3. do i really need a new case? i am planning to install a rear fan in my old case. there is no option to install a fan in sidebar of case.

 

[sparestuff]

I would try go for an Antec high current gamer 620W PSU, it's great quality and will be enough for any graphics card. The PSU you listed, the 450W corsair will be compatible with the mobo but if you add an amd r9 260X, you might be pushing it a bit, as the quality of the PSU you wanted isn't overly good, trust me and get the Antec HCG one, it is very reliable and has more than enough Watts to power your PC.