The Spectraview software supports all flavors of Eye-One (Pro (Rev A and D), Display One, and Display Two), the Spyder 2 and 3, Optix XR/DTP94/ColorEye, ColorMunki, and the NEC-branded version of the i1-2 Display that is tuned to work with the 2690 and 3090 panels.
Of the sensors on the list, the Spyder 3 and i1-Pro are going to be the best choices for the PA241W. The dedicated NEC puck may work as well, although we have only characterized a single sample, so can say nothing about the unit-to-unit variability standard i2 Display pucks exhibit. The Spyder 2 is comparatively inaccurate and produces large errors with wide-gamut displays. The Optix XR has real problems with wide gamut displays. Both measured white point and color chromaticity values are way off. The i1-2 is better in this regard, but still inaccurate for LED backlights. It also has high average unit-to-unit variation, so whether any particular unit is accurate is questionable. Recent Spyder 3 pucks (2009 and newer vintage) are OK for unit-to-unit variance (3x higher than the DTP94, half that of the i2 Display) and can at least get in the ballpark for wide gamut, LED backlit panels. Older vintages of the Spyder 3 varied wildly unit-to-unit, so measurement quality was a roll of the dice.
On the spectro front, the i1-Pro is accurate and repeatable except in the shadows. For luminance values below 0.5cd/m2 the measured values get swamped by sensor noise. You'll likely see compressed shadow details and some color casts to the lowest levels. Other than that, the results are fine. We have only characterized a single sample of the ColorMunki; based on the results, it is not high on the list of measurement devices you want to use.
The NEC-branded i2 Display sensor looks promising in terms of accuracy with NEC's wide gamut panels. Again, based on our measurements of 17 different i2 Display pucks, there is a wide variation in accuracy. Whether the NEC-tuned puck is a good overall solution or the sample we characterized was a particularly accurate one, I can't say. Quato sells a tuned version of the DTP94 that, from their data, appears to provide both the superior accuracy of the DTP94 in standard gamut ranges and reasonably good accuracy for wider gamuts. We have not measured one of these pucks, so no direct experience.
A drawback to NEC panels in general is that they use a proprietary communication protocol rather than following the DDC standard. This means that you are stuck with NEC's calibration and profiling software for controlling the monitor hardware. NEC' s head is buried in the same sand as the digital camera manufacturers who refuse to support open standards for RAW file encoding. The hardware is good, but the software is not up to the level available from third party vendors. We saw better results in terms of neutrality, smoothness, and lack of banding by first running NEC's software to calibrate the display and then building a profile using ColorEyes than by using only NEC's software.