Well, your budget is not very different from mine. I built a CS5 system a month ago. It really pays off to purchase everything separately and building yourself. Macs are nice for daily laptops but Mac Pros are a complete rip off that don't make any sense (IMO anyway). It's also funnier
My build was essentially:
i7-3820 (SB-E quad core; you can go hex core for $500 on microcenter, but that's double the price; there is no oct core i7). Price was $270, now is $220 on Microcenter (ouch!)
CoolerMaster Hyper212+ CPU Cooler ($20 on Microcenter)
Asus P9X79 Pro (around $320, Microcenter)
Antec 902 v3 ($100, BestBuy)
PPC Silencer 760W PSU ($80 Microcenter)
16GB G.Skill Ripjaws Z 1600 ($95 newegg)
eVGA Nvidia GTX 570 HDSC ($290 newegg)
Crucial m4 128 gb SSD ($145 amazon)
2x Hitachi 7200 RPM 2 TB ($145 each, newegg/microcenter)
24'' Dell monitor ($180, Bestbuy)
Pioneer BD-R (model is 207 or something) ($80, amazon)
I might be forgetting something.
I am not counting software and other useful accessories (keyboard, mouse, hdmi cable, card reader, speakers, etc., but this is not expensive; I also got an UPS).
I guess it should be around $2100 counting absolutely everything (including the unexpectedly expensive UPS, and excluding software).
I would recommend to get the hex cores i7 only if your budget can be raised as to still get the other quality parts (specially motherboard, RAM, and GPU). Also make sure you get an nVidia GPU for Adobe, because of the CUDA cores.
EDIT: I forgot to mention that this works as a charm with Adobe Premiere Pro and editing HD videos. Also all the games I threw at it, it plays them at max settings with no hassle (didn't try the MOST demanding ones like BF3, but the ones I like, e.g. Skyrim, work great). You can also try with i7-3770k and a Z77 motherboard, overall it will be a bit cheaper and performance will be roughly similar I guess. X79 has some advantages, specially for video editing, but it depends on your needs actually.