Rental BC's are usually designed to go with the rental reg, so the hose is on the reg not the BC.
About 80% of the time a standard inflator hose should do the trick so adding a hose with a standord QD to your reg would be the way to go.
The other 20% of the time, you may encounter rental BC's with a Air2 type of dual purpose inflator requiring a different quick disconnect or a BC with a Sea Quest QD on the hose. The sea quest QD is nice in that it is pre-cocked and idiot proof to connect, but is very non-standard.
In either of these cases, the rental shop would need to add a suitable hose to your reg. Normally this should not be too big of problem but it complicates the rental process.
There is also the question of fit. An inflator hose that is too short and badly matched to the corrogated hose will make it impossible to properly dump using the shoulder pull dump. Too long a hose will leave the inflator floating around in odd positions and can be uncomfortable. That is essentially why inflator hoses come with the BC. So if you have a hose with the right fitting for the BC but that is the wrong lenght, you may still find yourself having to borrow one from the shop.
What it all means is that a BC will probably be your next purchase unless you dive one location and always rent from the same shop.
