[MrDK]

Using the visa waiver program (stamp on arrival) you can visit a total of 90 days in any 6 months period, however, you need to leave the country no later than after each 30 days. You can get a 7-day extension while in the country, but it still eats away of the total of 90 days.

A tourist visa is for 60 days with an option to extend for an additional 30 days in Thailand.

That should cover you for the first 180 days (a total of 4 entries to Thailand), as you still have the accumulative 90 days available after the tourist visa has been used.

What I am not sure of is whether you can get a 60+30 day tourist visa, by leaving the country (i.e. Malaysia) and apply at a local consulate. I have a hunch that it is possible at some consulates, but that it is getting more and more difficult.