I think you will find that you can indeed get to the frame as the truck's bed (other then the redesigned tailgate) is the same one that came on your 2000.
I have had both the Torklift and Happi-jac systems. The TL provided a MUCH more secure mounting system and is the only way to go for a larger camper. The HJ allows more flex into the equation which works well if you are taking your truck down trails and off-road.
2007 F350,SC,LB,4x4,6.0/Auto,35" tires,16.5 Warn,Buckstop bumpers
2007 Outfitter Apex9.5,270W solar,SolarBoost2000e,2 H2K's,2KW inverter,2 20lb LP on slide out tray,4 Lifeline AGM bats,Tundra fridge
95 Bounder 28' ClassA sold
91 Jamboree 21' ClassC sold