Long question

Hi

A few weeks back my pc started to bsod frequently mostly on errors related to the video card (r 6950 with 6970 bios used for around 4 years), at one point it would bsod right after loading the os. I switched to the deafult bios and it worked for 20-30min and then bsod, after a few days it became more frequent until the pc wouldn`t boot at all (led`s light up and then shut down). I suspected the video card so I removed it and tested it on another pc, all I got was a loud bang, sparks and smoke from the card. I concluded the video card was the problem. The pc run just fine for a few days after that on the integrated gpu (phenom x6 1055t) but then started to bsod again so I suspected the psu.
I`ve taken the psu out and cleaned it (it had a lot of dust inside) and now the pc runs just fine 2 weeks later. My psu is OCZ GXS600 and is around 4y old.

And now for the questions:

1. Is it possible that the psu has sustained permanent damage? I plan getting a gtx970 and I wouldn`t want it to have the same faith as my previous card.

2. What psu would you recommend since I plan getting also an i5 4690, h97 mobo and 16g ram. I plan on using it for at least 4-5 years. I favor this local retailer http://ift.tt/1GZylE8 and my budget is around 500ron (local currency,~115euro).

Thanks

Long question