Well... It really depends on individual body.. I have a friend who feels that 29degree is cold. She always sneeze after every dive. But still she don't wear a wetsuit... Just a 3mm top as it is a hassle to wear it. But i will just wear a rash guard for Tioman waters.. It's more of protection to my skin than anything..
A cheap place to buy wetsuit I feel, is Dive Asia at Parklane Shopping Mall. You can check it out there. They also have lavacore which is fleece inside instead of neoprene. Keeps you warm and easy to wear too.
Note: I have no connection with Dive Asia. Just went there to buy my FDXi and Omega 3. I like to buy stuff from them. Friendly staff and everything is reasonably priced.