Origi, who started in Belgium's World Cup quarter-final defeat to Argentina, will cost £10 million while it is expected winger Marković will move to Anfield for £25m.
Liverpool have already brought in Emre Can, Rickie Lambert and Adam Lallana for a combined £39.5m and the latest two transfers will take their spending up to £73.75m.
The Reds also had a £20m bid rejected for Southampton's Croatia centre-back Dejan Lovren at the weekend, although the 25-year-old is determined to force through the move.
Suárez could complete his protracted transfer to Barcelona for £75m this week, although it is unlikely Alexis Sánchez will move in the opposite direction.
Origi, 19, scored Belgium's winner against Russia last month and was preferred to Romelu Lukaku in the knockout stages.
Marković, 20, only joined Benfica from Partizan Belgrade last year and helped them to the Portuguese title and Europa League final.