Yes, correct. Separate ticket machine for vans! Also possible to order a van from Grab.

From memory there are options for larger vehicles at the public taxi rank.

I normally travel alone and either use an AOT Limo, Bolt or public taxi into Sukhumvit from airport based on if client is paying or not. This trip its 4 people with luggage, can I pick up a van suitable in the taxi ramp or Bolt and do I need to pre-book Thanks 

I think avoid the chain based optical shops, Top Charoen is the leading company and are very expensive. Independent places are a lot more reasonable with options that are stylish but not necessarily designer brands. That said, convincing a Ladyboy to take a regular brand over a designer brand will take some doing!

When I by glasses for me and the Mrs they try the same hard sell. I just say no. Hers usually cost 9k, reading only. Mine were 13k for reading at different distances for work. I wouldn't say you were ripped off but you paid for a fully loaded package with expensive frames I would guess. Back on the subject of dentistry,  I am now half way through having my teeth realignment with Invisalign trays. Cost of treatment 100k, equivalent price back home in the UK would probably be slightly more than double that. Dental work here is top class and cheap compared to most of our home countries.