I have installed the temperature sensors, and have wired them to the same box. This box will contain the PICAXE and the RF transmitter. I have sensors measuring; Inside Temp, Outside Temp, Roof Cavity Temp, Exterior Wall temp (Measured from inside wall).
Took a LONG time to solder the wire... The cable is 8 gauge, and is made from the smaller copper fibers (like the ones you find in hook up wire). Should be a really strong connection :-). This cable is what I will use to hook to starter motor to the positive of the battery.
I have ordered the MOSFETs needed to make the switch, and I am waiting on the batteries, and the HUGE blocking diode (25ish Amps!!). To be honest, I don;t think I need one so big, but if I'm wrong, there goes $20 worth of MOSFETs...