Avionic Install/Replacement Certification

Again this is hypothetical. At the moment I am toying with the
possibility
of pursuing the credentials to become a certified avionic technician.
Thanks.

If you want to repair radios, you will have repair and return to service
authority only in association with a certified repair station. So your
choices will be limited to working for a certified repair station which in
english means an established avionics shop, or opening your own repair
station and being the certified repairman for it. You can't just work out
of the back of your pickup truck and be a certified repair station. See
Part 145.

If you just want to install radios yourself, you can become an A&P and don't
need be an "avionics technician." Or you can install the radios yourself
and get somebody licensed to check the work and sign it off, which is the
preferred method if you're not looking a new career.