The best option is a taxi if you're looking for comfort and immediate availability, but be aware that prices can be high.
The journey from Suvarnabhumi Airport to Trat takes around 210 minutes by taxi or other transport. Both options offer similar time and price, so the choice depends on your convenience and preference. Check current prices and schedules before deciding.
If budget is the main concern, consider checking all transport options and choose the cheapest available. Remember that prices can vary depending on the provider.
For families prioritizing comfort, a taxi is the best choice due to its privacy and convenience, but keep an eye on the cost.