Triple monitor setup upgrade ideas?

Current specs:

Intel Core i3 2100 @ 3.10GHz
4.00GB Single-Channel DDR3
ASUSTeK Computer INC. P8H61-M LX (LGA1155)
2048MB AMD Radeon HD 6570 400 w
400W PSU

I need to upgrade this rig to handle three monitors simultaneously (three Dell U2414H units—my current card tops out at two, and there's only one PCI 2.0 x16 slot on the motherboard).
My assumption is that this means a new GPU, a new power supply, and at least an extra 4GB of RAM.

Primary use: programming, graphic design, video editing... very little gaming.

Budget: $667, though I can push to $833 if it actually makes a significant difference.

1 x Gigabyte GTX750Ti OC 2048 GDDR5 128bit
1 x DDR3 4GB (1x4GB) Kingston, 1600MHz, CL11, Value
1 x Fractal Design Integra M 450W, 80+ Bronze Modular, 36mo warranty

$611 ADM

The GPU has 2x DVI and 2x HDMI ports and only draws about 70W, so I guess some cheap, low-end power supply could probably handle it. But if you’re planning on upgrading later and want peace of mind, just go for it.

You could also grab a 120GB SSD, though it might be a bit slower than its full potential since your motherboard lacks SATA3. It's worth it if you don't mind reinstalling Windows and everything else. 😬

I think the HD 5770 can handle a triple-monitor setup, and you can find one used for about $133
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