You do not really want the raw data (it generally looks something like this[1], from the COR telescope, "FITS" format[2]. Warning: mix of ascii and binary). Anyway, this[3] links to where they are putting the raw and first-order-derived mission data they have released so far (if you want more of what you saw, you probably want SECCHI). And here[4] is an example of said derived data. And this[5] seems to be where they seem to be putting highlighted derived products for public outreach.
Generally, there is very little money and little expertise for polished public outreach efforts (they are scientists, not web developers, after all). There is a good chance the scientists behind [3] are doing some of it in their "spare" time. Feel free to drop them an email and let them know it is appreciated :)
The image in the article is also not really low-res. As far as I can see Stereo’s CCDs have a resolution of 2048x2048, the image in the press release is 1280x720, that’s not exactly a substantial reduction (also considering that the two images from the two spacecraft were heavily distorted to create this side-view of the sun).
Don't vote him down, that's a valid point. Much NASA data is made public, but it might not be linked from this particular site. I would recommend looking around and seeing if you can't find it.
I wish NASA would release versions in whatever the native dimensions/resolutions they are receiving the image data back in.