BleepingComputer.com: Will this plan work out?

I'm going to buy a new computer and it's a prebuilt one. This is the computer that I'm planning on getting (better/more detailed specs here.)

I'm planning on also placing in a new graphics card. I have my sights on a Radeon HD 4650. To do that, I'm also going to need a new power supply unit. I have this one in mind.

I just have two questions:

1. Will this setup work? I'm hoping that this power supply has enough juice for this GPU as well as the rest of this computer. It's a 500W compared to the stock 300W that's included in this PC. I'm just wondering if this sounds like enough. I'm not concerned about having more than i need. If it's not below minimum recommendations, I'm fine. I also do not plan on having any SLI/Crossfire setups. That's a bit overkill and not really something I'm interested in.

2. Will heat be an issue? Again, I'm not really into the whole SLI/Crossfire setup and I'm most definitely not into overclocking.

And if it helps, I did a little research on the computer and it turns out that this is the PSU that's included in the computer to begin with.

that should work, but for that amount of money, I would think you could build your own system from scratch that would match those requirements if not better and last longer. I have no respect for gateway computers, have seen several ones that just quite simply were junk and failed long before they should have. they use cheap parts, especially the motherboards, they used to use almost exclusively ECS boards which failed often, and they may have changed, but I still dont trust them. Building a system isnt that hard :D

Sparkle makes a decent power supply

I'd love to build my own system from scratch, but my parents just need a new computer and don't want the hassle of putting one together. Since it's going to be shared among us, I figured that I'd throw in just a few of my own parts so i could actually play my games on them ;)

just promise to go through all the hassle for them lol but no I see where your coming from. that should work, Antecs a good brand, though I think Id get a higher rated one that then. it will do the job but is rather weak, I would check on newegg theyd have a better lineup. I typically trust Coolermaster, Antec, Corsair, and OCZ PSUs. for video cards if your going ATI, I will emphasize this, you CANNOT go wrong with a saphire card, I strongly recomend them. I put saphire cards in all my builds, both personal and for customers and never had a problem with them. they are good, dependable cards I would stick with them.