Photoshop :: How To Work With 8 Bit Images Without Posterization

I'm aware that one "should" work in 16 bit and I ALWAYS do for my own stuff but for clients, I'm very frequently limited to 8 bit images because that is all they have to supply. Most civilians just don't know about this stuff.

For instance, I'm doing the graphics for a CD cover right now. Luckily the client knew enough to send me images that were large enough to work with but all of the different source images were in 8 bit. So, I'm now on the home run stretch as far as finishing this job but I have an image that could REALLY use some punching up in the way of curves or levels adjustments. I'm finding that even with what I would consider to be very modest adjustments, the resultant image ends up with a histogram with a whole lot of pretty major holes the entire height of the histogram. Now, I see absolutely no posterization on the screen but I've read that even in that case, it could very well show up in the print.

So, here I sit after doing about 10 hours of work on this project and can't really finish up the last couple minutes of work necessary for good contrast and color without screwing up the histogram. I don't want their prints to possibly be posterized but I also don't want to send them a fairly flat looking image.