visa for trailing spouse (Bangkok)

Hello, I was wondering if anyone had experience getting a visa for their trailing spouse? I have been offered a consultancy that will last a year and a half, and while my employer will arrange my visa and work permit, they are not willing to do so for my husband. Because he is a writer, he does not need a work permit, but we would like to ensure that he is 100% legal to be in the country with me. I realize some people just make multiple visa runs, but that isn't ideal, especially as I understand it's actually not permitted for long-term stays. (Again, even if it's "technically" illegal but not enforced, we can't risk it, as it's not like he can go "home" if caught.) I'll be in Thailand for three months before he comes to join me so could sort this out there.

Does anyone have any advice for me based on your experience with a non-working spouse? Type of visa, etc? Things to watch out for?