So, the installation of the ELT panel control went pretty smooth and came out actually really nice. The ELT antenna installation also went in pretty well. Having the antenna mounted between the horizontal stab and the vertical fin is probably less than optimal but on the RV-8 there really isn't anywhere else to mount it because the canopy slides all the way back to the Fin. The location I chose is a common place that many RV builder's mount their ELT antenna, so at least it will be in good company.
Mounting of the actual ELT itself posed a bit of a head scratcher. The installation manual says that it needs to be mounted to a structural member and *not* to the skin of the aircraft. The logical place to mount it would be in the rear baggage area where it could be accessed in case of emergency or for servicing. But, this is just .25" skin and not particularly "substantial". So, I added a .063" skin stiffener and also tied it into the left fuselage longeron with the two existing mounting screws. It seems very stoutly mounted now and is quite accessible from the outside of the plane.
I built a special RS232-to-GRT GPS Module cable that also has a set of power leads for powering up the GPS. With this cable and the software downloaded from the Garmin web site as previously discussed, I was able to reprogram the module for 9600 baud (default was 4800).