Best HAA - 429 w/7500, 145 or 135  

to fly it over 7000.  It's pretty simple; just lower the collective a bit and you'll land with fuel.  Most pilots are operating this aircraft at 90 QT which is perfectly within limits but you don't get much more airspeed between say 80 and 90 QT.  Just fly it at around 80 QT and the burn rate is reduced dramatically. You're only going to miss out on 3 to 5 knots and extend your range enough to not have to fly it over gross.  I've been flying the 429 for 10 years and have never had a reason to fly over gross.  Just practice basic airmanship, play the winds, file if you need to get higher.  More altitude means better efficiency, cooler temps, less stress on dynamic components, higher true airspeed etc.