Well...if you go the direct route....there is no ducking in if a problem arises and you are out of the range of TowBoat/SeaTow. My recommendation is to take her up from St. Augustine to Fernandina outside on an overnight shakedown. Tiger Marine there is good and can fix anything that you find wrong.
From there you can take another day jump outside to St. Simons island/Golden Isles marina. If all is well you can then head offshore on a rhumb line for Charleston...but still be able to duck back inside at Bewfort or Savannah should the need arise. From Charleston and with more confidence in the boat you can head offshore around Cape Fear and into Bow-Fort...with Southport/Cape Fear as an interim stop if needed.
If there are no problems along the way I make the trip 6-7 days which is a couple of days longer than the straight line but probably advisable.
I assume you will prepare the boat for offshore with appropriate safety equipment, Epirb,liferaft etc. May I also suggest a battery operated GPS with extra batteries and spare impellers and lots of Racors. If you do not have a spare alternator, I'd also carry one of those automotive "jump start" packs in case the alternator fails and drains the batteries.
Again...the
Doyle Guide to SE US inlets is a must have for this trip!
Good luck with the trip!