A 7870 needs a 500w psu with two 6 pin pci-e connectors.
In theory, your psu will do the job.
But... the Thermaltake TR2 is a tier 5(not recommended, replace asap) unit on this list:http://www.eggxpert.com/forums/thread/323050.aspx
And also, if your objective is gaming, as indicated by your gpu upgrade, then a FX-8350 will not be a very good change.
Few games use more than 2-3 cores, and the bulldozer cores are slower than the new intel cores on a clock for clock basis.
A 2500K or 3570K would be better.
The SSD is a wonderful change; you will never go back.