We are moving this coming summer to Singapore from London. We are a family of 4. Two kids age 3yo and 6yo. My kids attend a selective private school here and we are very happy with the results. To carry on this path we thought to applied to Dulwich college Singapore (first option) and UWCSEA.
Today we received a letter from Dulwich saying my youngest was accepted for Reception and my eldest as well but he is on the waiting list as Y3 is full and we should wait until April when there is usual movement.
Also, today a letter from UWCSEA arrived saying both of my kids are accepted to start this August 2019 and we need to reply by tomorrow Tuesday! It seems a bit pushy? Considering they know we have an appointment with the head of Admission this Saturday in London! 
I feel that we should wait for Dulwich as we are planning to come to the UK in probably 4 years (who knows! that is the idea) so the kids can carry on with the British curriculum, mainly my eldest which will be in high school by that time. Would be really IB very much different?? Would IB curriculum put him below the level required to pass an entrance test in a selective UK private school ?
I heard very good reviews about UWCSEA, but it is very uncertain of what the entrance criteria is? We just sent the school reports. Dulwich based their decision on school reports and also on my sons test, which was done remotely.
Please can I have some points of views or experience? I am really panicking
..... Anything that could help us would very much appreciate it.