Actually Samraong has never been a big touristy spot so you'll just find some very basic guesthouses clustered near the dirty little market, which is advantageously located right next to the taxi station.
This is a simple but clean place with a bed, mosquito net, fan (for a part of the night, as electricity may shut down) and share bathroom going for 10,000 riel.
The Meanchey Guesthouse is likely the most conclusive one among these with some NGOs visiting. This place is similar to the Rikreay, only the power stays on for twenty-hours, which means your fan should stay on all night. A room with a share bathroom, net and fan is US $ 4 and a double room with a simple bathroom inside of it is $10 - expensive for what it is but you are paying extra for the power. The US$ 4 room is so to say the better deal.
In fact that there aren't that much tourists staying overnight there are 3 very basic guesthouses in Anlong Veng. The most convenient one is the Reaksmey Angkor Guesthouse in the North of the small town. You will find quite clean rooms with mosquito net and a bathroom. The price is around 15,000-25,000Riel.