There are only very basic accommodation options in the immediate vicinity.
Cambodia: the village at the foot of the mountain provides two or three very basic "guesthouses" in simple wooden shacks.There is also a wooden, very basic guesthouse shower and toilet outside at the bottom of the steps, where the locals live. Shower is from a barrel of rain water and a bucket. Very, very basic but very clean. Electricity from 6PM to 10PM.
Thailand: the nearest place with a variety of accommodation is the town of Kantharalak approx. 30 km, which is also the nearest place with direct bus services to Bangkok, Si Saket, Ubon Ratchathani, etc.
More distant Thai-side possibilities are the towns of Si Saket approx. 95 km, and nearest train station, and Khu Khan approx. 95 km, and most convenient place to stay near the border if travelling to/from Anlong Veng; and the city of Ubon Ratchathani approx 120 km - however, the most direct access to all these places is via Kantharalak.
If you have your own equipment, there is a campground in the Khao Phra Wiharn National Park. Call the Department of National Park, Wildlife, and Plant Life (http://www.dnp.go.th) at +66-2-562-0760.
