" wrote:

....snip...

Might be better to call a pro. I'm also wondering
about if the location even makes sense, ie there might
be a better location, more convenient, etc that you
could do with about the same work. I can't recall
ever seeing a garden hose bibb located on the
cold water intake line of a water heater.

It sounds to me like the OP wants to make the installation as easy as
possible, i.e. one fitting in an already exposed run of pipe.

If everything after the WH goes up into a finished space, it might be
difficult to tap in anywhere else, especially if he doesn't even want to
cut that one pipe.

That said, I'd still look into the PRV situation since the OP seems to be
concerned about too many turns in the hose reducing the pressure. Tap in
before the PRV and pressure probably won't be an issue.