Okay, so for my unprofessional opinion... I would get a good UTH for the warm side. those ambients are a little on the low side, but if you get a good UTH that can get your warm side surface up to around 90, I think you'd be okay. With that size tank and the infrared light, you may need to add a second water bowl to keep humidity up... maybe not, but just try it and see.
I personally don't care for the log hides at all. They can hold bacteria, they are hard to clean, and they are not as closed in and as tight as some other types of hides. personally, I really like the type from Reptile Basics (which you can make your own with some old plastic bowls or flower pots.
For your temperature and humidity, I would keep the sensors near the floor of the cage, since that is where your snake will be. If you have the digital gauges, even better, as they are easier for us beginners to use (they're sometimes more accurate as well, depending on the brand).