Will my video card fit in my motherboard?

[Kigenso]

So a year and a half ago I bought a Dell XPS/Dimension 420. Yesterday, my Geforce 8800GT died, so here I am!

All the new video cards require a stronger PSU than my current one (I only have a 425W psu), so yes I know I'll have to upgrade. I was thinking of getting:

http://www.amazon.com/Coolmax-Nvidia-Certified-Modular-Design/dp/B000G702RI/ref=sr_1_4?ie=UTF8&s=pc&qid=1260061468&sr=1-4

Is that a good PSU?

I was thinking of getting either the ATI radeon 4850 or the 4890, but I am not sure if it will fit in my motherboard properly. Here are some pictures (not the best quality) I took of the insides of my computer:

http://img19.imageshack.us/gal.php?g=img0601dx.jpg

http://img13.imageshack.us/gal.php?g=img0604d.jpg

A friend of mine said that my motherboard is backwards, so getting a PCI 2.0 card wouldn't fit properly because of the black box would be in the way (no idea what it does, I think it funnels air to the cpu?).

What do you guys think? I was thinking of getting either:

Radeon HD 4850
http://www.powercolor.com/Global/images/assets/PCIE_HD4800_4850_1GB_HDMI_PCS/PSD/image_b_s.jpg

or Radeon HD 4890
http://www.dinokomp.si/images/PowerColor%20Radeon%20HD%204890%201024MB%20Plus.jpg

Any thoughts? Thanks!

 

[TimboAK_49]

welll...considering you probably dont have pcie 2.0..i would save some bucks and look into a 9800gt for your rig

http://www.newegg.com/Product/Product.aspx?Item=N82E16814150316&cm_re=9800gt-_-14-150-316-_-Product