Which MAC would be best for photography?

[Meghan]

I am on Apple.com trying to buy the best iMac 27" that would be best for me. Of course, i'm thinking that the BEST thing to do is buy the "best of the best".. BUT that would cost me over $3.000 bucks and i don't want to pay that miuch for stuff i won't even use. I'm really just wanting to purchase something that would be enough to do what i do(and a few extras).. which is photography. I shoot in raw and need something to hold large files, and maybe a few HD videos.(along with photoshop, music, maybe the sims HAHA, and all the "essentials" i may need for my career).. I know for sure I want to buy the 8GB(2x4gb) because it's not TOO expensive and not the smallest about of gb..and since it's the 2x4 i could always add more. BUT I don't know what to do about the Processor or hard drive. I don't know if it's worth the $150 to upgrade to the 2tb ATA Drive.. or if i should just stay at 1tb.. Also i don't know if it's worth the extra $200 to upgrade to the 2.93ghz i7 processor. I just need someone with a lot of computer knowledge to let me know what will be best!