You can get cheap and strong pumps from Aquarium shops all over Sinagpore.
There a quite a few Aquarium shops near Clementi MRT that sell a wide variety
of water pumps at very cheap prices. The rough location is here.
The 2 brands I have had good experience with are Dymax and Ocean free. Both
are pretty cheap and have a range of products to choose from. I bought the 1200L/hr
Dymax pump for $ 11 only and find it silent, flows well and reliable.
This should be sufficient for a nice performing rig. If you crave more flow
to squeeze that bit more performance out, or if you have many blocks to flow
through, you can opt for the Ocean Free 2200 L/hr pump for only $ 29.
It is a very powerful pump and I dare say more than enough for our use. These
pumps are submersible which mean that they must be subrmerged in a reservoir
of water for them to work. There are also inline pumps that do not need a reservoir.
There are less of these kind available in the shops and they are more expensive.
One good inline pump you can get is from the Eheim range but they are quite