As far as the cooling tubes, you could use square 1/4 tubing or round, your choice. It does greatly help reduce the oil temps at the pan. I used to own the MSP pan.

It would also be nice to have a temp port added as well as the drain. The MSP pan had a block welded to it and holes drilled into the block and then the two holes were 1/8NPT. 1 you could drain the fluid out of and the other was used as a temp port. they were facing 90* from each other.