So four questions:
Can I run that card with that power supply?
Should I just buy a power supply? If so what one for that card?
What is the best card sub $180 for my power supply?
I have installed ram, video cards and hard drives how hard is a power supply to install?
Way more power supply than you actually need, but the Combo Deal is ridiculous so you might as well. For $165 after rebate you get a $90 power supply and a $140 video card.
4)Installing a power supply is very simple. However time consuming compared to RAM or a GPU simply because you have to disconnect and reconnect all the power cables. It just takes time to do that. Otherwise, it's usually as simple as 4 screws. So far as power connectors go, they're all sized and shaped differently so you cannot plug them into the wrong places. The trick is making sure you plug in all the same ones you unplugged. That way everything works.