I am getting ready to order the parts to put my engine back together and I will need a gasket set, along with the o-rings for the head, crank halves, and all the bolts that require the sealed washers.

Do the o-rings and sealing washers come with the gasket set?  I imagine the valve seals and oil seals would have to be ordered seperately.  The parts diagrams to not elaborate on what is in the gasket set.

Suzuki branded kits have most everything.
o-rings, sealing washers and all the gaskets.
They don't include the valve seals.

I haven't split the case, so I'm not sure what's required there.

Typically you can reuse sealling washers, valve seals must be gotten separately.