Hey Home, long time no see! Hope things are well, still have your sweet zoas
I'd go with live sand so you don't experience a mini cycle. Not that I have a whole lot of faith in those bags of watery sand..Carib Sea makes them.
Frankly, if you go that way, I'd test for ammonia before adding it to the tank.
I see that Carib Sea (what you will find as 'live sand' in most LFS's) has now changed the way this product is marketed and the sand comes dry and there is a packet of something in there to make it 'live'. I have a bag but haven't attempted to use it yet. I can't imagine that it would suddenly become live by adding the magical packet.
If you're not in a rush, you might want to take a little sand out of your DT, put it in a bucket with the new (dry & rinsed) sand, add SW & a PH and let it seed itself outside of your tank and then add it in. Shouldn't have any mini cycles doing it that way
...oh, and maybe a heater if the room is A/C'd