Investors looking for sources of passive income to fuel their retirement dreams face a dilemma. Should you chase high yields from slow-growing businesses or invest in lower-yield providers with more predictable cash flows?Lately, Pfizer (PFE 0.17%) and Prologis (PLD -0.52%) have been perfect examples of the trade-off between attractive yields and dividend growth. Pfizer offers a sky-high yield that's climbing slowly. Prologis offers a much lower yield, but it's been raising its payout at a remarkable pace.H ...