I understand the need to try and start the day with maximum battery power, but sleep takes very little power. But, no, I don't know of an elapsed time shutdown. If you think you might forget and leave it sleeping, you could set it to shutdown at like, say 2am.
As an example, I've left mine sleeping, then driven for 11 hours and had plenty of battery left (on both my 17" PB and 2.33 MBP. My 17" UB wouldn't even notice, since it has roughly twice the mAh). If you leave it sleeping for a few hours and then consistently run low on battery, it sounds like you'd need a 2nd anyway (in other words, even if it was shutdown, you'd run low).
I think you will be missing a great feature of OS-X on a portable: the virtually instant wake. Normally, I only shutdown or restart when needed for an update/install, maintenance (booting off another volume), or Bootcamp. (and, once in a while, for a problem that's easier to resolve by a restart). Otherwise, it's sleeping. I sometimes go many weeks without a restart.
edit: I think by "hybrid" you mean "Safesleep", in Apple-speak. AFAIK, you will only go to Safesleep if there is no power whatsoever (i.e. the battery is run to the shutdown level, or you unplug w/o a battery installed - that's how you can swap batteries when sleeping. When you remove the battery, it automatically resorts to Safesleep recovery.)