I went through the same thought process when I built my -9. I did not want my ELT behind the rear bulkhead, where it would take a tool and a good bit of time to get to it.
While different than your -8, this might give you an idea or two.
I cut an access hole in my baggage compartment floor and mounted the ELT trail to the side of one of the floor ribs. The trap door I made is held in place by some oversized thumb screws. I thought they might be in the way but that has not been an issue. My thinking was that should I be hurt in an accident, I should be able to get to the ELT with one hand and attach the antenna.
The antenna has a couple of layers of shrink tubing on it so it will stay secure when slid in an adel clamp. The adel clamp is held in place by one of the screws that secures the flap arm on the right side.
Here are a couple of pictures:

(Click to enlarge)
__________________
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
www.repucci.com/bill/baf.html