Thread: Koh Kood/Trat to Siam Reap

I am taking a trip to Koh Kood in a few days with my girl and after that trip I am considering going to Siam Reap for a few days to do the temple thing. She will go back to Bangkok for work and I am thinking about crossing near Trat, but have never been to Cambodia and have read on the boards here about the area charging more for visas than they should. I am thinking of making the crossing there and going to Phnom Phen to take a look around and then on to Siam Reap by boat or bus. Any information on the crossing there or information that would make my trip easier is appreciated.

Another consideration is that I have a single entry visa that is up August 1st. How will this crossing effect my return to Thailand and departure back to the states at the end of July?

Thanks