I was originally planning on running a custom intercooler. After playing with the stock one and calculating flow rates of other aftermarket intercoolers it became pretty clear that the stock intercooler was a pretty good fit for what I needed, and it's free! I will just have to get its fins straightened and give it a good cleaning and it will be ready to go.
I am going to cut subtle but effective venting slots in between the head humps and use a couple small electric fans to draw air into the intercooler.

To mount the intercooler I threaded a couple 1/2" aluminum bars at each end. One end screws into the engine block and the intercooler bolts into the other end. I think they look pretty clean and they are surprisingly sturdy, most importantly they weigh almost nothing.