Definitely a sick machine. I had the 3.4GHz one and I sold it because it was more than I needed.
I'd recommend checking out the refurbished models to get the best deal. Apple refurbs are pretty much the same as buying it new and you can get some great deals.
I'd look at this one
Refurbished iMac 27-inch 3.4GHz Quad-Core Intel Core i7 - Apple Store (U.S.) Basically the top of the line version. Only thing missing is the 2GB video card and the additional internal HD, but you can just use an external HD for each if you need extra storage.
27" 3.4GHz with 256GB SSD. The SSD really makes a huge difference.
Pop some Crucial memory in that thing for cheap. It's like $80 to upgrade it to 16GB (why the fuck not?).