Right now, Shuttle Fleet is really the only option. SSU is far from complete, and really no one should try to fly it unless they are trying to bug hunt or assist in its development somehow.
Shuttle Fleet and the use of certain MFDs you will be able to closely mimic realistically flying the Shuttle.
Use IMFD to do all your burns, dont use a throttle or the numpad to burn OMS pods, because in the Shuttle you could not just punch a throttle.
Use Pursuit MFD to keep the orbiter under constant attitude control and to keep it in the proper attitudes for the various phases of flight.
Use Sync MFD and the rendezvous script with the Terminal MFD to do realistic rendezvous.
Use RPOP MFD that comes with SF for proximity ops and to do things like the TORVA.
and use the heck out of GPC MFD and all it has to offer. It has 1 of the launch screens, it has both essential Deorbit screens, it has the MPS/OMS screen, SPI, a screen that simulates PLB door opening, a table for setting present arm motions that can be called up in the PDRS screen.
And it has AutoFCS which you can use for automatic control of deorbit from the burn down to Mach 2, where you can turn off the control axis and leave on the Flight Director and fly it by hand down to the runway just like real shuttle pilots did.
SSU has APUs. SF does not simulate the APUs. Or any consumables. And you cannot destroy the vehicle. So you will need to impose those limitations on yourself.