i have 12" apes. i'm 5' 11'' they are great for me. i have the pushed forward so they are straight up. don't let the dealer walk all over you. all you need is a longer clutch cable break line and turn signal harness. your stock throttle cables will fit 12'' apes. as for installing, i did it myself. took me probably 6 hrs. really isn't hard, but it is a pretty big mod so take your time and be patient. it is always fun wrenching on your own bike.
My buddy runs the 12" mini apes on his nighty. Hes about 5'9 and he loves them but says he is thinking about going to 16s. Im 6'1 and his bike feels comfy to me. He got the apes and the extra length clutch cable and brake line for about 70 bucks from our local hd shop, then we ran internal wiring on them (was a complete bitch but looks so good.) All of the cables and wires (outside of the clutch and brake line) still reach perfectly fine, even after the internal wiring.