u can rent out ur current house purchasing the second house. normally if u can get tenant that can pay >85% of ur house installment considered quite good already. that way, u just need to pay the 1.5m house that u live in ±15% of that 600k house.

personally, I rent oout several of my house at ±90% of my monthly installment. landed & no maintenance fees. so every month I just need to cover 10% installment of each house. and once a year, need to fork out own money for cukai pintu. Anyway, it didn't burden me at all.