For game development, that is overkill. He needs a graphic card setup that is as powerful as needed for testing, unless he's making games only for super mega extreme PC gamers. Devs try to be as efficient as possible with resources so their program can run on a wider range of hardware configurations. Also that cpu isn't really up to par with that graphic card setup, he's not going to get the best performance out of it. Plus he'll unecesserily have to deal with heat issues and a component runs slower when its hot. Also those prices are kinda scary, you can find better deals on the online.
Graphics Cards: 2-3xASUS ENGTX590/3DIS/3GD5 (3 GB) (~$900 each)
- Personally i'm gonna throw in 2 of these to run in SLI, but the mobo has room for 3 so it's possible to run Quad-SLI