We have a factory-installed Hoyt Jib Boom and it's really great for single handing!!!
I'm not sure what you mean by an "ankle smasher".
It does require permanent modifications and, like all things marine, is expensive.
You're right in your presumption the regular working jib for this set-up is less than 100%.
We also have a 135% Genoa the previous owner added. In an emergency, it can be furled and controlled by the boom, but, as sailingdog points out, it's far from a perfect set-up.
One issue I would caution you is to consider how the rigs you're thinking of will work at, or near, dead down wind. The Hoyt has an optional "extender" which we don't have. Without it, it's virtually impossible to sail wung out in less than 10kts of wind.