hi!is it worthy to keep my thermaltake litepower 700w psu for my new zotac gtx980ti amp 6gb?i have this psu since 2011 and the warranty is over.also,whats the best ande cheapest ups and psu for a system like that,including i5-6500, 16 ddr4 ram,250 gb ssd, z1 170 asus pro gaming motherboard,1 tb sata?thanks!