Since you already have a 780 I'd say the cheapest option is to simply get another.
Otherwise if going for a completely fresh build, 900 series all the way! The 970 is almost as good as the 780TI at a fraction of the price.
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Samsung, Intel and Crucial are the only SSD brands I really trust. The Samsung 850 Pro is probably the best value currently if you want the highest performance, otherwise the 840 Evo is a great lower-cost option that is almost as fast in practice depending on how much data you are writing to the drive.
For hard drives, Western Digital are my favorites, go for the Black drives if you want really fast hard drives, otherwise the Red drives are the best option for a more cost-effective quiet drive if you want to cram multiple ones into a tight space (great for a server or NAS with a lot of drives).