How to better communication skills perfectionist, detail oriented, somewhat introverted person?

This is hard to get across. My personality style is VERY detailed, big picture and perfectionist. ie, judgemental, opinionated and quick.

I have been told I'm VERY good at quickly surveying a situation and thinking of solutions and the affects of all parties. I'm good at teaching technical skills and detailed, complex things (like mail requirements and printing technology) - and that I have high expectations and an ability to set clear expectations and manage them consistently. Also that I have an ability to consider other people's personality styles and drivers. So I've had some great successes at leading operational departments and processes.

What I lack, however, is the ability needed to excel in a sales function. I show frustration readily when it's evident, I tend to solve problems that may not need to be solved, I lack confidence in approaching customers that haven't requested my shpeel and I lack the ability to say somethings in a 'politically correct' manner. I'm pretty black and white and can be abrasive sometimes and taken wrong - although I CAN read people and learn their personality styles, it's not something I can pick up on quickly within a few moments as a good sales person can. I'm not talking about wanting the ability to sell ice cubes to eskimos. What I'm talking about is getting across sticky subjects with finesse. The ability to 'sugar coat' without seeming like I'm sugar coating.

Can any of you suggest on-line classes or places to look or titles of classes - I'm unsure what to call it. "Interpersonal Communication" classes such as offered by Fred Pryer or Career Track are ones I've taken, but they're pretty general and often for people just beginning to learn to interact on any level or needing improvement. I need a more specialized way of being coached perhaps over time.