My biggest concern at the moment is if the new card will fit. I specifically chose this one because of its small size and single gpu/fan. There's also a wifi adaptor on the pci port right below the video card that is screwed at the end, leaving only enough space for a slim fit video card. Is it likely that I have to remove this and install it on a lower pci port?
If there is a small size video card out there that performs better than the GTX 650 TI, please recommend. And I prefer to stick with nvidia with this one.
You need a new psu too. http://www.amazon.com/dp/B0092ML1SC/?tag=pcpapi-20 Size isn't a concern, you have space all the way to the front of the case. The wifi card will need to be moved regardless as the 640 is the best nvidia single slot card you will find in the US.
There is no airflow in the bottom of the case without the gpu. But this really doesn't matter as your case really doesn't have airflow if it has no front fan. I can't find if it does or not. The 650ti is relatively cool and you could always just leave the side off.