I'm planning on using one of these:
Bulkhead Connections
To pass both AC and Coolant through
I'll also get new lines fabbed up at a local place, but similiar to
these.
I'll also be planning around the same time to be tucking the wires and mounting them more centralized behind the engine to further hide the connections using
More Bulkhead Connectors
Just to give you an idea of what's going on.