Looks great man! Is that yellow heart I see in there? Give an end grain cutting board a go, they are super durable! I use CBdesigner (just google it) and it helps with the planing and layouts for end grain design. Its crazy the designs some people can do with end grain boards.
Just food grade mineral oil. You don't want any chemicals near food and no oils that will go rancid (such as vegetable oils). End-Grain cutting boards take quite a bit longer to make and they add a lot more waste in sawdust from the extra cuts, but they are totally worth it. If this board gets oiled regularly it should last a life time and never show any sign of wear.