You can diy, many bus goes to border from ekkamai bus station, last bus is 11pm, first bus is 5am. poipet is good, just pay 200 to get the cambodia to stamp in and out. avoid ban leam, they are greedy to the max.
I got called to their office to have a chat very very often now. As I have 8 years of in and out. Now I got married. Going to get a marriage visa. As I have max out tourist visa. 2 years ed visa. Countless land and air. If you are back to back. Most likely they will ask questions.
60 days is a tourist visa, that you can extend for another 30 days = 90 days. You can do that in cambodia, laos or penang. Just need passport, and money and a photo.