LP stands for liquid propane, which can be run at either low or high pressure. Low pressure typically refers to anything 1psi or under, and high is anything over. I'm not familiar with that particular burner, but I know the similar looking jet burners operate on low pressure (either NG or LP depending on the orifice). Low pressure is usually slightly cheaper to automate with safety features, but either one can be automated. For low pressure, a standing pilot valve (honeywell VR8200 or similar) with a thermocouple and pilot assembly is the cheapest and easiest way to automate "safely".