I m thinking of 750w just in case I go for sli in future. 970 seems more vfm. I live in poojappura. Are u from Tvm rijin?Get seasonic s12ii 620. It is plenty. It is not good to use a high end gpu like 980 with a 450w psu especially an old one as the combined 12v o/p(power hungry components demands 12v) on 450w will be around 400w(most gives 360w only)and considering capacitor aging,get a new psu.
Ot: Where do you live in Trivandrum?