RGB-Working Space for CMYK Images

As many of you probably know, if you are working with an cmyk image in Photoshop, there aren’t quite as many possibilities as there are with an RGB image (e.g. filters, etc.).
This is why I am looking for a RGB-Working Space for CMYK Images which fits best for any standard cmyk gamuts.
The ideal profile would be a conversion of one of the standard cmyk profiles (e.g. Euroscale coated) to RGB.
Is there a profile like that yet, or does it have to be made?

I am not completely sure I understand your question.

Most people consider sRGB to come close to SWOP CMYK, but for years and years I (and many others) used Adobe RGB (1998).

Work in RGB, and soft proof the CMYK via your properly calibrated and profiled monitor.

Just to expand on Richard’s point. If you “Proof Colors” in Photoshop, under the “View” menu, you can get a visual proof of your image in SWOP CMYK and still work on your file in RGB mode.

There are colors within SWOP (and I define that as TR001 and the U.S. Web Coated (SWOP) v2 profile) that fall outside the gamut of most sRGB type displays and there are colors that fall outside of sRGB (mainly Cyans and some greens). As such, you might want to consider Adobe RGB (1998) which fully contains SWOP gamut.

You can’t soft proof colors that fall outside the display gamut of course.

You can’t print colors that fall outside the gamut of the working space.