I think you should take a fresh look at your budget priorities. The display is actually much more critical than the computer, and it will impact your work much more directly. If you really can't go very much above 1000, a good 24", like the PA242, is way, way better than a mediocre 27".
Spectraview (and Eizo ColorNavigator) talks directly to the monitor's internal hardware. It doesn't adjust the video card like the Spyder. This gives you a whole other level of control and precision.