Need your help!

[Mirsie]

So I have my current "dream" pc part list, but I need a PC sooner than I will be able to afford everything, so I need something to start with and upgrade from.
At the minimum, I need to be able to browse the web, run microsoft word documents, and multitask well, since I'm a student. I also need a wifi adapter, mouse and keyboard and I don't have a case or any spare parts.

This is what I have picked out for my finalized build until I'm richer, lol.
CPU: Intel Core i5-4590 3.3GHz Quad-Core Processor ($188.99 @ NCIX US)
Motherboard: MSI H97 PC MATE ATX LGA1150 Motherboard ($88.99 @ Mac Mall)
Memory: PNY Optima 8GB (2 x 4GB) DDR3-1333 Memory ($67.48 @ Amazon)
Storage: Western Digital RE3 1TB 3.5" 7200RPM Internal Hard Drive ($48.49 @ Amazon)
Video Card: Gigabyte Radeon R9 270 2GB WINDFORCE Video Card ($149.99 @ Newegg)
Power Supply: Logisys 550W ATX Power Supply ($19.99 @ Amazon)
Optical Drive: Lite-On iHAS124-14 DVD/CD Writer ($13.99 @ Newegg)
Wireless Network Adapter: Rosewill RNX-N180UB 802.11b/g/n USB 2.0 Wi-Fi Adapter ($9.99 @ Amazon)
Total: $587.91

I would like to stay around $200, maybe up to $300 if need be.

Please tell me this is possible so I don't buy this:
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=8992352&CatId=2628
and ruin my upgrading capabilities, lol.

 

[Mirsie]

I've also found this http://www.walmart.com/ip/34083875
which seems to be upgradable to an extent.

What are your thoughts?