If you haven’t already done it yourselves, I was able to set up this for my warlock to switch gear and talent builds.
#showtooltip
/equipset [mod:alt] PvE; PvP
/lon [mod:alt] Demo PvE Cleave; Demo PvP
Line 1: displays the icon for the equipment set in the equipment manager.
Line 2: equips the equipment set. I named them PvE and PvP.
Line 3: Changes the talent loadout. I named mine Demo PvE Cleave and Demo PvP.