What components can I salvage for a possible rebuild?

I am considering rebuilding my gaming PC next summer for both gaming and schooling purposes. Since my gaming PC was the first PC system that I built, I would like to ask which parts from the list I am providing below could be salvaged and re-used for a new build. The list that I am providing from pcpartpicker.com contains the components that I used when I built the system in late December 2013 and early January 2014. I would like to point out that since I built my system, I have added an ASUS Xonar U7 sound card, replaced my ASUS GTX 770 with an ASUS GTX 970, and boosted the RAM from 8 to 16 GB using four Corsair Vengence RAM sticks. Also, I haven't decided on this but would like to go ahead and ask it as well: If I rebuild the system I am considering the possibility of moving up from a GTX --70 to a GTX --80 video card but would instead go with the flagship of the preceding series. Based on the history of past video cards, if I do go with a GTX --80 such as a GTX 1080 instead of a GTX 1170, would the GTX --80 of the preceding series be more powerful than the GTX --70 of the succeeding series? Here is the list of the parts for my build:


Component Selection Price
CPU

Intel Core i5-4670K 3.4GHz Quad-Core Processor
CPU Cooler

Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler
$29.49 Buy
Motherboard

Asus Maximus VI Hero ATX LGA1150 Motherboard
Memory

Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory
Storage

Samsung 840 Pro Series 256GB 2.5" Solid State Drive
$199.89 Buy

Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive
$61.00 Buy

Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive
$61.00 Buy
Video Card

Asus GeForce GTX 770 2GB DirectCU II Video Card
Case

Corsair 600T Silver ATX Mid Tower Case
Power Supply

SeaSonic M12II 650W 80+ Bronze Certified Semi-Modular ATX Power Supply
Optical Drive

Asus BW-12B1ST/BLK/G/AS Blu-Ray/DVD/CD Writer
$99.89 Buy
Wireless Network Adapter

TP-Link TL-WDN4800 PCI-Express x1 802.11a/b/g/n Wi-Fi Adapter
$38.88 Buy
Case Fan

Aerocool Silent Master 200B 76.0 CFM 200mm Fan
$20.98 Buy

Aerocool Silent Master 200B 76.0 CFM 200mm Fan
$20.98 Buy

Aerocool Shark 82.6 CFM 120mm Fan
$10.98 Buy

Thanks in advance.