Anyone know where I can pick up a meditation cushion? Doesn't much matter which kind (zafu, gomden, etc.). Thanks!

There's a factory shop in Bo Sang, called Siam Cushion or Siam something or other. It's on the main craft street when you turn left off the road that goes to Sankampaeng. It will be on the right side about 200/300 meters after the turn from the main road. They don't have cushions made specifically for meditation but they have a large selection of many sizes and styles. The cushions are filled with kapok.

check the shop near the northeast corner of the old city opposite the moat.

It's between the bicycle shop and wicker bamboo place.

They can make all sorts of mats and cushions. They use good quality foam that does not deform over time.

Great source for exercise mats also.