How about the Better Toy Store? It has Plan Toys which are made of wood and non-toxic.
It also stocks Wheelybug (wood), Pintoy (wood), and Selecta (wood).
When your child gets bigger, you can even consider wooden play furniture like kitchen sets and wheelybugs, entirely made out of wood!
http://thebettertoystore.com/brand/plantoys.html
IKEA
http://www.ikea.com/sg/en/catalog/categories/departments/childrens_ikea/18738/
You can also visit these online stores which stock wooden toys:
Right Brain Babies
http://www.rightbrainbabies.com.sg/products/wooden-toys.html
Smart Alley
http://www.smartalley.com.sg/collections/wooden-toys