First, don't waste your money on 4 GB of VRAM on a card of that class. The very most the card would be able to handle is 2 GB. More likely 1GB.
Second, that would be pretty much a sideways move: http://gpuboss.com/gpus/Radeon-HD-5830-vs-GeForce-GT-740
What is the resolution of your monitor?
What is the make/model of your power supply? Look on the nameplate.
Is $120 your budget limit? Because $120 will only buy you a GTX 750 which is marginally better than the HD 5830: http://gpuboss.com/gpus/Radeon-HD-5830-vs-GeForce-GTX-750
OK. Since your PSU is capable and you will be gaming at 1080p, the only thing keeping you from getting a recommendation is your budget and the processor it will be working with. No sense suggesting a GTX 780 Ti if your budget is only half that or if your processor is a Pentium 4.
My processor is an AMD Phenom II X4 955, and my budget it flexible, would like to keep it around $200, but willing to possibly go higher, just gives me suggestions so I can think about it.
My processor is an AMD Phenom II X4 955, and my budget it flexible, would like to keep it around $200, but willing to possibly go higher, just gives me suggestions so I can think about it.