One company's dividend is as close to a sure thing as you can get in investing. The other is a bit riskier but potentially higher reward. Together, they are a perfect match.Tractor Supply (TSCO 1.34%) and Starbucks (SBUX -1.97%) have both established themselves as dependable dividend payers. Yet, their strengths, risks, and income profiles could not be more different. Tractor Supply, the leading rural retailer, has a smaller yield but comes with a track record of measured growth and strong coverage. Coffee ...