My HDD drive of choice is the WD Black 2tb 7900 rpm 64mb cache. My question is this. Does my hdd of choice affect performance or will a 2tb green work just as well cause of the ssd?
The WD Black may benchmark slightly better than the WD Green but you will not notice any real-world difference between the 2 drives when using Intel SRT.
BTW how long will the SSD last, cause I read somewhere that since I'll be using it for caching it might not last that long.
Not true. Don't worry about drive longevity. You will upgrade the drive or it will fail for other reasons long before it runs out of P/E cycles.