The three wire SI alternator is definitely the one to use, built in regulator that is easy to test and replace and simplifies the wiring. I have my sensing at the dash where my junction block is. I fed the junction block with a #8 wire then ran another # 8 to a second junction block at the rad support. You may as well go with the ford style starter relay while your at it as that is also a good place to connect accessories, the cable to the starter is only live when starting and keeps the start wire from the ignition switch away from heat, great for connecting a remote starter switch to as well. I found the junction block on the rad support great for hooking up the fans, head lights, horn and using to power a timing light, kept all the wires on the number one spark plug side of the car.
Bluebird, how did you run your charge wire to the battery? It doesn't look like the charge wire was connected to the side where the big cable comes from the starter relay back to the battery in the pic of the starter relay. Why wouldn't you connect it there if you didn't like in this example? Also, where exactly did you mount that starter relay? I can see that it is close to an inner fender, but which side?
