Depends on how anal you want to be. None of those beautifully modelled palms from the Model Tree Shop are actually found in SE Asia at least not in the wild. In general terms, you will mostly want Cocos nucifera, the common coconut palm. Sugar palms are common but date palms would be a rarity.
Pegasus do two packs, the ‘Type B’ pack are coconut palms. The Type A, could with a bit of work be used for other endemic species. I have had both and my observation would be that, whilst they are reasonable models, they are fairly fragile, the fronds brittle and the plastic was a bugger to paint. There’s only three to a pack so they are hardly the most economical option. All things considered the Woodland Scenics ones are better value for money.
Overall, I’d echo the response to look on ebay or Ali Express. There are god knows how many Chinese vendors selling palms. Choose carefully some are just child’s play set quality but there are some good models there too. A number of sellers, particularly on Ali Express sell bulk deals.