dont go for a 450w psu as in future u might have some lags with ur pc as i think you are going to use a 1GB graphics. I would suggest you to spend some more bucks and have lifetime of relaxation. Go for a >500W psu. Antec VP550 is one of the options. Below are some links for PSU/case per your requirement:
500W PSU: Antec VP550 550 Watts PSU | Psu | Flipkart.com
Case: Antec ONE S3 Mid Tower Cabinet | Cabinet | Flipkart.com (It comes with front USB3.0 * 2) One of the best case in the given budget.
Graphics: I will recommend the same as above. Its one of the in the given budget
do you have any idea about gfx cards ?? 1GB gfx card will lag with a 450W PSU ?? many 1GB and even 2GB powerful gfx card will run just fine using a 450W god branded PSU and 2 yrs. warranty will offer life time relaxation ??
For Op's rig Corsair VS450 ( which is available at 2.1k ) is more than enough - with his present config he can even run cards like HD7850 / HD7870 easily.