Graps,
I hunt with a 66" bow as well and have a climber with a bar around it that i hunt out of everytime i am in the woods. My advice would be to set the top just slightly below where you usually set it and lay the bow across your lap is what i do. the only thing that matters is you not moving while the deer are looking at you. The best thing is to see/hear them before they get out there on you. If they walk out and the bow is still laying in your lap, wait until they eat or look away and then stand it up.
With my set up(climber with bar) i have to be extra observant of limbs above me. I had a potential shot at a deer last year that i didn't take, because i was contacting a limb above me.
My best advice would be to practice a few times to understand and learn moves/shots that you can and can't do in the stand. Try to simulate the whole scenario, from sitting to standing to shooting behind you, to how close you can shoot them without worrying about your bow hitting the bottom of the stand, everything imaginable.
Good luck,
I hope this helps, Daniel