Quite digging trash out of the office dumpster. lol That is not too bad a build. You are limiting what he can do on his system. Let's get realistic, anything Intel graphics sucks ass. One of my small thumb drives has three OSs on it. A 2TB HDD with a 60GB SSD on a $500 dollar budget build? You chose storage instead of giving him more processing power. The Antec 620watt ... PSU you chose is nice for what little it costs. No I did not notice he said he was dual booting. Linux was what I would have recommended anyhow. Normally I would give a Nvidia GPU for better drivers, but at this price point it would be better to choose a good APU.
First off all... Explain to me how am I limiting OP's abilities with this build over your much more limited AMD APU FM1 build that doesn't even perform on the same CPU level? Shit, for the same price, the Gigabyte mobo I selected supports both SLI/xfire setups and faster 2133 ram if he wanted more upgrade options over your mobo.. Even then, I could have easily gone down with a cheaper $60-80 H61, H67 chipset motherboard to save some costs and still meet OP's requirements.
Why does he need a beefier gpu core? Read his requirements:
As of now, the plan is to use for general web-surfing, light duty tasks, but I want the possibilty to add a good quality video-card and SSD
Second, the list you linked is just adding a 2TB drive to the $400 list above it; you can easily budget in a $100 gpu if you wanted to add gpu potential that will beat your APU selection while staying on a more standard lga 1155 socket motherboard that has loads of features. And even then, like I said before, OP's X4 setup is a better choice to match his needs than your AMD APU solution.
Third, i3 2100 series chips are not slow for cpu processing abilities. Dual core with HT and is between the X4 965 and 975 BE at stock speeds for $113?!?! Yes plz. Even beats your FM1 APU by a wide margin. While the IGP HD 2000 gpu core is not very fast for gaming, its more than powerful enough to handle daily tasks, web browsing and HD video; even some older games like TF2. You really don't need more than that for a low budget $500 build, specially if OS isn't needed in the costs.
Fourth, I added a 60GB SSD because its cheap and for his requirements of a desktop browsing computer, even for dual boot, it would be enough. OP also mentioned that he wanted
the possibility of adding an SSD. I just showcased that he could in fact afford an SSD on his budget and PC requirements. He didn't say what apps he would be running, but even then, the OS will be very fast and responsive for his needs, then install programs on the optional 2TB drive or whatever sized drive he goes with. I only selected the 2TB in case he wanted more space and there was room left in the budget to add one in; still best $/GB right now even after the floods. Prices will go down to more normal levels, but we are almost there.
Also, the PSU deal is now over so just replace it with a cheap 400-500w psu from a brand name maker for the same cost. You can grab the 600w OCZ for $40 still on newegg.