Thanks for the input, both of you.
Most of what I've owned have been 50mm macros, but I did have a 35-70 Nikor macro, and although they were good lenses, I was thinking a really fast macro in 50mm (I'm familiar with the macro distance) would give me more light-gathering capabilities, and therefor more DOF. I need to get a standard lens to replace the cheap kit lens that came with my camera, anyway, but wasn't sure I wanted a 35mm or a 50mm or a 14-55mm. The link MJ provided convinced me to go with the 50mm. (For maximum quality and light-gathering capabilities, with this switch from Nikon film to Pentax digital, I've decided to go with all fixed lenses and just move my lazy bleep back and forth.)
DOF, to me, is the biggest problem with macro, because I'm concerned with making illustrations, not "art," and years ago I began carrying a hand mirror in my camera bag, and when I wanted a macro, I'd hold it off to the side so that the sun reflected directly upon my subject, flooding it with light and giving me enough light for a better appature (more DOF) and still enough shutter speed for hand-held.
Macro before was sort of a toy, an accessory I rarely used, but this time I want to create some really stunning macros.