from work experience bigger is better, get the deepest one the low profile in my opinion looks worse but it also doesnt have the side pockets under the lid over the bed rails standard.

i have a husky diamondplate i have had one before that one is now on one of our other company trucks its a good box, rest of our work trucks have the weathergauard diamond plate box, deep and wide enough (front to back) to put most power tools in and tool bags in and is the most secure and durable box there is...size security durability next one i have will be weatherguard