^^^ ohh you already have iball cabinet and PSU, then you may buy 4670 that way you can use your older cabi+smps(still not recommanded), 9600gt will require atleast 1.5k smps only...ur from chennai right?? then go to richie street(do some exercise) and buy the palit one, their you will get other components too which are not avaliable at ur local shop.., and performance wise 9500gt(512mb)<< 9500gt(1gb) << hd 4670 << 9600gt, btw you have net connection?? its always better to read ur own rather rely on othres, these infos are easily available on internet.. just google around for "9600gt benchmark" or "9600gt vs 9500gt" "9500gt 1 gb reviews" like that...you will get all ur answers with statics, benchmarks..
if you search for "PSU for 4670 forum" and select mode "pages from india only" probably you 'll get results like this
*www.techenclave.com/graphic-cards/will-intex-450-w-psu-allow-128313.html
read the above thread carefully...