Thailand perfect for DN families, phuket Chalong area is good if you do not like crowded places. You can find a decent villa with good internet. Stay away from the tourist locations
Coffee Tribe is a really crowded and trendy place in Phuket with amazing selection of brunch and breakfast. They have Wi-Fi available so you can carry forward your work while enjoying the rustic surrounding. I
Stash Phuket is a coworking space which provides accommodation too. Its located in a rainforest and is pet friendly too. They provide free parking, co living, swimming pool and many other amenities to work from.
Phuket International Airport- You can grab a free sim card from TRUE MOVE counter which is for tourist basically. It gives free 3G for 30 days and you can always have a top-up from any 7-11 store.
Probably the most comfortable co-working space in Phuket. They have a great ambience with 5 day passes costing 1000 THB. Hatch has various meeting rooms and the fastest WiFi I could find in Phuket.