Need to know if GTX 460 is compatible with my PC?

Hi again guys. I've been appreciating the help so far and I am three days away from getting the funds to purchase my new card. I have been intently looking at the GTX 460 (ENGTX460-PCIE-1GB-CO-R), and I'd like to know how to check my PC to make sure I'm gonna be good to install this.

Again, my build is:
Acer Aspire AM3470G-UW10P
2.2 GHz A6-3620 AGP (2.5 GHz Turbo Boost)
Onboard Radeon HD 6530D
4GB RAM
300w OEM PSU

Yes, yes, yes, the PSU is coming out as well, definitely gonna get at least a 450w if not more. But I want to make sure my PC can support all these requirements that are listed. Again, I'm new to this so I'd appreciate any help as how I can check and make sure everything is on the up and up.

•Product Requirements:
•Two (2) available rear expansion slots (Does this mean two of those little filled in slots with nothing in them? If so, I'm good, I have 4 of those empty.)
•Available PCI Express 2.0 x16 slot with available adjacent slot (I know there is a PCI-e x16 slot on the mobo, but it doesn't specify in the specs whether it is 2.0 or not. I've hear that PCI-e is backwards compatible? Also, this "available adjacent slot"? Does that mean this is gonna need two PCI-e 2.0 x16 slots or is this gonna cover up another slot? This is my biggest question mark.)
•Two (2) 6-pin PCI Express power connectors (So I need to find a PSU with two of these available?)
•DVI or HDMI display (Check.)

Thank you again everyone. If you need any more info, please ask. I'll do my best to answer so I can get a good idea of what I need.