Fish help! i have a 125 litre tank and i need help on what fish to get?

hi i have a 125 litre tank with 1 rainbow shark, 2 clownloaches , 1 pretty tetra , one golden mollie, 4 guppies , 1 gourami and two scissor tail things. i was wondering are cichlids hard to look after,aggresive and can they go in my tank? if not can you please leave any suggestions of really cool fish.. thanks a lot! ps. if you give a good answer i will give you lots of POINTS!