Having a cool side is good this way he can thermoregulate his body temps. My tanks are 82f on the warm and 79f on the cool, I know it doesn't seem like much but it makes a difference to them. If that's all he you get though they also burrow to do the same thing, all my guys spend more time burrowed on the cool side most the time. For the water bowl I do the same as you and put it right smack dab in the middle, this way when they cross from side to side they have no choice to go through the water. The will usually stop and sit for awhile once they hit it too, or they will take a huge dump in it for me to clean. For placing it I would place it on the cool side or closer to the cool side if possible, but to be honest some place on it the cool end and some on the warm.