Help with HTPC BUILD

HEY FOLKS......first time visitor, but have read a lot and you guys are good. I am hoping that you can help me out with my first build. Below is what i am after and i would like to go under $500 (closer to 400 ) if possible.

Programs i run (sometimes simultaneously):
Photoshop CS3 + bridge
Itunes
IE
Zoombrowser
Picasa
Gaming is limited to Madden football (maybe once a year)

I am primarily photo involved and would like to make this pc double as a dvr at which i will hardwire via hdmi to my 60 in the basement and stream recorded tv and movies wirelessly to my tv's upstairs via media extenders. I hope i have given enough info here.....help me out please! I already have a 250gb external hd.

thanks much for the info. How do the above processors compare to the intel core 2 duo??
My current pc is a dell dimension 4600 2.6ghz, 80gb hd, 1.5 g-ram. how with the aboves compare?

thought i would share with you what i came up with earlier at work....for some reason i could find the info in my initial post, sorry bout that, question is "does all this stuff work together and is it any good":

I would also like to consider what you have and/or combine or intertwine some things!

mobo+processor combo:
http://www.tigerdirect.com/applica [...] CatId=3586

ram:
http://www.tigerdirect.com/applica [...] u=C13-6082

hd:
http://www.tigerdirect.com/applica [...] =TSD-750AS

burner:
http://www.tigerdirect.com/applica [...] CatId=1624