Gigabyte vs XFX - Radeon 4850/4870

So with my build this summer, I'm building an AMD AM3 quad-core gaming computer. The components I've picked so far:

Gigabyte MA790FX UD5P DDR3 motherboard
Phenom II X4 955 BE
4GB Patriot DDR3-1333 CL7 memory
Corsair TX750W Power supply
Cooler Master Storm Scout case (+ two 120mm Antec TriCools for side panel)
Western Digital Caviar Black 640GB
Samsung DVD writer

I have my key and mouse but I'm having trouble choosing the correct graphics card for my needs...At the moment, I have a spare 19" 4:3 1280x1024 LCD monitor that I'll be using IF I can't afford a newer monitor. My wish is to purchase a 24" WUXGA (1920x1200) monitor as well but budgetary concerns are crucial at the moment.
ANYWAYS.
Worst case scenario I don't purchase a newer widescreen monitor, I was going to go with either a Radeon 4850 or 4870....leaning towards the 1GB versions of both, seeing as the pricing is the matter of $20 extra or so and more VRAM couldn't hurt...Even if it doesn't affect performance @ 1280x1024.
At my resolution, I'm confident both will max at any of the games I play (Company of Heroes, CoD2/4, Fallout3/Oblivion, FEAR, to name a few).
Right now @ DirectCanada.com, where I'll be buying all/most of my parts, a Gigabyte Radeon 4850 512mb is selling for ~$105 after rebate. The 1GB version is selling for $125. Both these cards have a Zalman VF850 (I think, could be a different model but it is a Zalman cooler for sure).
The other brand/cards I was looking at was the 4850/4870 1GB offered by XFX...About $10 more than the Gigabyte.
Both seem to have pretty good feedback from users. Heat is definitely important for me in my setup and depending on that, I'll probably be OC'ing my card as well.

My question is this:

Between the Gigabyte brand 4850's (as well as the 4870's, depending on if my budget allows it) and the XFX offerings, which one would best suit my needs? I like the fact that the Gigabyte runs cooler MOSTLY than the reference designs used by XFX. Although from what I've read, because of the Zalman cooler's design I won't be able to tweak fan settings. Noise is NOT a huge concern for me but not hearing a jet engine beside me would be nice to keep the temps down. I don't mind tweaking fan settings to lower temps as much as possible. I have read, however, that the reference 4850's get REALLY freaking hot, not exactly appealing to me.

What do you all think?

The extra warranty is definitely a plus. I hadn't been looking at other brands other than XFX until I spotted the Zalman cooler on the Gigabyte...The fact that it is cheaper definitely caught my eye as well but if I decide the warranty's worth the few extra bucks, I'm definitely picking up an XFX card.

One question though...Between the 48xx 1GB cards, what's the performance increases like? I've been looking through benchmarks for quite some time and either a) lose the sites that answer my questions and b) don't include all 48xx radeon's in the benchmarks.
If I'm gaming at 1920x1200 (eye candy preferred...nothing more than 4xAA required though with a bit of AF thrown in), which cards would be a better value? I don't intend to purchase any of the upcoming next-gen DX11 cards, not until they mature a bit at least, so I'm looking for the good price-performance card that will serve me the better part of the next year.

I'm torn between 4850 and 4870. There's a good difference in price but if I'm stuck at 1280x1024, is a 4870 1GB even worth it? And if I do upgrade my resolution, would a 4890 be a better investment at 1920x1200 than a 4870 1GB?

I'm not sure exactly how my finances will go through within the next month or so so the difference between the cards for price is a concern (which is why I'm not even bothering with a nvidia offering...The cheapest GTX 260 I can find is the same price as a 4890!). I know I'm probably over-analyzing this, seeing as a 4850 1GB and a 4890 is only about $100 difference.

Oh, and sorry about this thread. I'm sure 4850 v. 4870 v. 4890 has been discussed to numerous lengths on this forum.

Not after tax.
DirectCanada (and NCIX as well) are based in British Columbia and only pay 5% GST, as opposed to newegg with GST + 8% PST.

And free shipping after $300