@coldfish this GF recipe looks like the least whitewashed of all the ones that i saw.
https://www.mybfisgf.com/recipeindex/laksa
the soy sauce probably isn't the most important so tamari would work fine. it's the fish stock and coconut cream are more impt i think
if you want a taste reference for yourself while making it i would suggest ordering the laksa from noodle station in daly city. it's most like what i like.
using rice noodles is common so it's already celiac friendly but i also like 'shirataki noodles' made from konjac