No, no, no. Don't make them yourself. We have a custom molding supplier here in the Springs that would cut that stuff quickly and easily. Assuming they can do it with stock tooling on their molder (likely), there's a $35 set up charge and then probably a couple bucks a foot. They can do tens or twelves or whatever you want. I'd have them run extras and then just set them aside till you need them.

White oak will fare better outdoors than common red oak. The pores are smaller so it doesn't absorb moisture as quickly.

PM me with the profile if you want me to look at it. The molding house is wholesale only or I'd just send you to them directly.