SCB, Kasikorn + Kungsri are all easy and don't need a WP, just an ID and an address. If your in a hotel, rent a condo so you have a residential address. Also it would be far cheaper.
The school term ends in June here so I will be free to travel then. I can apply a90 day or 1 year O visa here but that will mean my wife sending me our wedding certificate to China.