REITs are the perfect income instrument for an income investor as they are required to pay at least 90% of their profits as distributions.However, not all REITs are built the same.Income investors need to sift through the sector to identify the reliable ones that they can buy and keep for their retirement.Here are four dependable Singapore REITs that you can own for life.Parkway Life REIT (SGX: C2PU)Parkway Life REIT, or PLife REIT, is a healthcare REIT that owns a diversified portfolio of 75 properties wor ...