ummm take my word for it if he wants to import 13 cats the Thai immigration is gonna shut him down - they are trained to look for red flags denoting mental illness / this is a no go situation - they will send him packing as soon as they see 13 cats
Yeah - unless your seriously wealthy your not coming to Thailand - 13 cats is probably 20 grand USA funds then the Thai government is not going to allow you to come because having 13 cats that you cannot live without means your a crazy person and Thailand has enough of those already