I look for a healthy animal 1st and foremost thats eating well and shedding well, anything after that is personal preference IMO. Colour, temperment, attitude, and appearence is all for the eye and the acceptance of the person thinking of purchasing.
Keeping any snake can be both a rewarding and fascinating experience and picking one should be a personal choice based on your own preference and ability to care for it.
Best of luck , look forward to seeing some pics when you make that all important choice.