For me, Yes he could do that, but no he doesn't need to.
1. I would go to a pretty balanced build with almost all parts at its latest gen.
2. He doesn't need to go with 7970 because it will be too much for his needs. I will go to a build that will suits his needs. Yes ofcourse he can go to what we say a future proof, with the difference of a 7950 and 7970, almost a little to none future proof between the two.
3. If he really wants to go with 7970, he can go with it without changing the parts, it will still be in budget. But I prefer a sapphire one. I'm not saying powercolor is a bad brand, I just don't go with a cheap brand and might cry later on. It will be something like this,
PCPartPicker part list:
http://pcpartpicker.com/p/y1Yd
Price breakdown by merchant: http://pcpartpicker.com/p/y1Yd/by_merchant/
Benchmarks: http://pcpartpicker.com/p/y1Yd/benchmarks/
CPU: Intel Core i5-3470 3.2GHz Quad-Core Processor ($149.99 @ Microcenter)
Motherboard: ASRock H77M Micro ATX LGA1155 Motherboard ($69.99 @ Newegg)
Memory: G.Skill Ripjaws Series 8GB (2 x 4GB) DDR3-1600 Memory ($46.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($69.99 @ NCIX US)
Video Card: Sapphire Radeon HD 7970 3GB Video Card ($369.99 @ Newegg)
Case: Corsair 300R ATX Mid Tower Case ($67.41 @ Mac Connection)
Power Supply: Corsair Builder 500W 80 PLUS Bronze Certified ATX12V Power Supply ($51.98 @ Newegg)
Optical Drive: Samsung SH-224BB DVD/CD Writer ($22.98 @ Newegg)
Total: $849.32
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-01-17 01:09 EST-0500)
4. But I would still prefer a 7950 over a 7970 for his build, cheaper but still suits his needs. (Changed the 7950 to a regular one, I think the first post was with a OC one)
PCPartPicker part list:
http://pcpartpicker.com/p/y1ZS
Price breakdown by merchant: http://pcpartpicker.com/p/y1ZS/by_merchant/
Benchmarks: http://pcpartpicker.com/p/y1ZS/benchmarks/
CPU: Intel Core i5-3470 3.2GHz Quad-Core Processor ($149.99 @ Microcenter)
Motherboard: ASRock H77M Micro ATX LGA1155 Motherboard ($69.99 @ Newegg)
Memory: G.Skill Ripjaws Series 8GB (2 x 4GB) DDR3-1600 Memory ($46.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($69.99 @ NCIX US)
Video Card: Sapphire Radeon HD 7950 3GB Video Card ($279.99 @ Newegg)
Case: Corsair 300R ATX Mid Tower Case ($67.41 @ Mac Connection)
Power Supply: Corsair Builder 500W 80 PLUS Bronze Certified ATX12V Power Supply ($51.98 @ Newegg)
Optical Drive: Samsung SH-224BB DVD/CD Writer ($22.98 @ Newegg)
Total: $759.32
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-01-17 01:13 EST-0500)