Upgrading Graphic card with PSU

450Watts?

I went over to my local market yesterday night, found 2 good company PSU,
one was ocz 650w with 85 % efficiency(according to the 60 USD tag and the dealer. the other one was Antec BP450S, 550 and 650 with 83% efficiency)
other than that all I found were local made. I Couldn't find much info about this series and since there were no VP series and kids getting up my nerves. I went with Antec BP450S, (I was feeling at least 550watts, but the guys there said 450watts is more than enough for my build and 650watts would never be needed, just waste of money) after a lot of convincing from him and showing his trust on his knowledge I got it installed today on my PC, it cost 32 USD(My fixed budget for PSU was 60 USD as I was aiming for 650watts)
was little bit skeptical about going with 450watts, but after installing this PSU, I felt the difference, very silent, no noise at all, much better power cables than my previous cheap one, although other wires not looked so premium but they are strong, that's what I got in my local market. not bad, I would say not the best either.
tested it's performance today with 112 F Room temperature, my kid playing saints row the third, resident evil 5, nfs hot pursuit, for over 3 hours long continuous along with me and the PSU worked nicely, at the highest with a geforce 210, that was lying around at my relative home.(my 9500gt didn't had a HDMI or higher dx for the experiment, PSU took all with such an ease and 210 was a pain in the butt).
So, I feel it's working fine. No power issues as for now. It's got 3 years replacement guaranteed, So, I will put it to great tests with my older gpu and see if they get burnt or not!

Now the last thing that is left for me is the GPU. I searched the whole market, but all I found there was
a load of crap geforce 210, HD 5450.
and newer geforce 710 craps
geforce 730 2gb ddr5 64bit
geforce 740 4gb dd3 128bit

seeing the 210 and 9500gt performance on my system, I don't think any of these gpu would make me happy anymore.
Now my option is to import a good GPU from a person who can from other place. since I saved some bucks from my PSU budget, and almost all other upgrades completed now.

I am confused whether even a 750ti 2gb ddr5 will be able to perform on 1920x1080 res, with this build at a decent 60fps? or it would even hit above 40fps on any newer games, or even on resident evil 5 for an example. I can't settle for anything less than 1600x1200 on the new HD TV.

the shop representative advised me AMD r7 series, which are better in performance than the nvidia. but would they be suitable for my build here? and not get bottleneck by my i3 processor? I don't want to overload anything here, and don't want to loosen up the processor, just the right mix.

as the GPU would be my last investment on this i3 build, I want to max it out now with the GPU. not going for a processor or motherboard upgrade for the next 2 years atleast. as I have already spent enough this month (around 250+ USD for the HD TV, PSU and RAM and keeping 200 USD for the GPU, total 400+ budget! just for the Full HD jump on my monitor.

Thank you for the advises though, really appreciate your helping in my problem.