Hi
At first glance, it appears that your card should run SC4 Rush Hour. That being said, SC4 was released in 2011. I know that it does not utilize more than one cpu at a time, and that you may have better luck running it by tweaking settings via command line switches and possibly adding your card to the game files. None of it is super-techy, but it can involve some trial and error. The game has also been notorious for random crashes, which may or may not be solved by these tweaks. There is also a reported issue regarding mods with the Origin version, if that is something interests you. With all that being said, there is a large gaming community out there that believe it's still the best SimCity game and tons of resources are around. One of the best sites for SC4 players is simtropolis.com, they have a very active player community. (also - it appears that you may be able to get a refund on SC4 after all) This post on How to Configure SC4 contains information on command line switches and other settings tweaks. You might want to give that a read-through before deciding.
Keep in mind that I don't have direct experience with SimCity 4. I do not claim to be an expert in this arena, and I hope that someone with more knowledge comes along to give better insight.
The most recent version, SimCity Complete (2013), should run fine on your card. On Windows machines, most issues with SimCity 2013 involve having a conflicting program that blocks the executable. The biggest culprits are Nahimic, an audio management program from MSI, and anti-virus / firewall apps which need to have SimCity.exe added to exception lists. There can be issues trying to run on Ultra-High-Def monitors & an occasional card that may need some settings tweaked in the preferences file, but for the most part the newer cards play nice with the game. SimCity 2013 has the choice to run in either multiplayer/online or single player/offline mode. Some players enjoy the challenge of playing regions with multiple cities; others complained that the multiplayer approach & inability to expand the city plot size are too limiting.
I hope this helps a bit. Whatever you decide - Happy Building!