A firm no?
The THG review link I posted above showed the entire system running on 136w of power - with the exact video card Obhasha has selected.
This review, specifically for that card, does show a higher consumption - but still only 168w.
http://www.overclockersclub.com/reviews/msi_560gtx_hawk/15.htm
Ob - you can run a review the power requirements of your system with the tool on this site ( I could not since you never listed your cpu):
http://extreme.outervision.com/psucalculatorlite.jsp
I suggest spending the extra couple of $ to get the Pro version - see link on above page - that will give you the requirement for each leg - the 12v leg is most important.
That said, I would never suggest that anyone buy a SunPro PSU - but hey you have it already. It is not a very good PSU since it allocates less power to the 12v leg. I have no idea how well, or poorly it is made. Run the test above - including the paid for test that calculated power on the 12v leg (its only a couple of $) and see what they recommend as a minimum.
Note that even if it has only 17a on the 12v leg, that is 204w - which is more than your whole system used on in the above reviews - and part of that power - albeit a small part - is 3v and 5v.
Also note that I googled but could find little info on that brand - but I saw several listings in Australia so maybe it is a bigger brand there. Not finding info by itself does not mean it is bad. but who knows? It is very important to have good power for a PC - it is not just to "power" the system, as we normally think of power, but it is the power broken down into infitessimally small amounts that are the lifeblood of the system and and the millions of calculations done every second. Newegg lists scores of brands, mostly at the low end, that I would never consider recommending.
If you want to learn more about PSUs, I recommend this site:
http://www.jonnyguru.com/modules.php?name=NDFAQs
Regardless, if you decide to use it would be a good idea to upgrade the PSU as soon as possible because you will have only a small margin of protection.
If your budget is tight, consider getting a GTX 560 without the Ti - which would save approximately $40 - and put that towards a new PSU. That would buy the PSU jyjjy linked above, which would be a good choice. Note that it has 34a on the 12v leg - or twice what yours does.