Good choice, especially if you do get a more powerful card.
Costs a few quid, but massive peace of mind to know that your expensive hardware has good quality powering it. You're set for years with that unit.
There's an absolute whopper on Tom's Hardware who says 850w Corsair units are mediocre but he's talking through his arse. He likes to pimp Seasonic units, but there is NO mediocre quality 850w Corsair power supply these days. He's a total biff, I'll take him on one of these days.
Hopefully the shop get you back up and running soon and you can start to enjoy your upgrades