750 W will be overkill (waste of money). For A SYSTEM WITH GTX 970, 500 W PSU is more than enough. You can get 520 or 550 W for future proof. Even when you upgrade to GTX 980 (just for instance), you need only a 520 W PSU. See: http://www.realhardtechx.com/index_archivos/Page362.htm
get this one
itll be perfect for you
itll run all your components just fine
best PSUs availible at this price
all the other PSUs from well known brands at this price are pathetic
750 W will be overkill (waste of money). For A SYSTEM WITH GTX 970, 500 W PSU is more than enough. You can get 520 or 550 W for future proof. Even when you upgrade to GTX 980 (just for instance), you need only a 520 W PSU. See: http://www.realhardtechx.com/index_archivos/Page362.htm
Shall I go for 750 ? In case if I upgrade things in the future?
if by upgrade you mean adding another GPU in SLI
then yes go for the 750W
otherwise all other things are going to get more and more power efficient in times to come( the maxwell architecture for example is way more power efficient then the previous series of cards)
other than that you dont need a 750W
even the upcoming broadwell CPUs are going to be more power efficient
Would you be putting a second GPU as an upgrade or upgrading the same card? If you're putting a second, 750W would be plenty. If you're upgrading the existing card, not adding extra GPUs then the 500/550 will be fine.
^ Even the 970 SLI needs only 700 W PSU, so he must be safe with 700-750 W PSU (he's not going to overclock CPU, but may be GPU(s)).. Even 750 is much plenty for crossfire, I would say.