From Kualar Lumpur to Thailand by bus

Hi
This is my experience in traveling to Bangkok from KL in 2014,
First you should go to Pudu Central Long distance bus station. It is best to book a bus seat previous day. So many brokers struggling to catch u. Book a bus to Hat yai , south Thai city. Or if you cannot catch a Hatyai bound bus, you can book a Changloon bus. Then u have to get off at a place a few kilometers before immigration counters. this journey is about 8 hours. Road is nice. Go to Hatyai city, Around main bus station , there are many places to stay at cheap rates. Next day you can travel to Bangkok. It takes about 12 hours to go to Bangkok, Phuket island is close to Hat yai.

You sure have a strong back and bum to sit in a bus for long hours. I surrender if travel same as you as I will opt for train so that I can stretch my legs or sleep in a bunk.
Salute you man