Megamart in landmark or The centre on Ramada junction have some selection of ready mix Thai spice. Alot short of souces and if you lucky you even can get some fresh lemon grass, lemon leaf, galagal or even fragrant lime. This are basic spices on Thai cooking. You know what I mean. For some more fresh herbs and spices selection sometime Lulu hypermarket have, if you lucky again. Good luck with your hunting.