I am finding this humorous. To answer ops question, yes the HJ system will work and is strong enough for your camper. No it will not interfere with fueling. I had HJ on our 01 Ford F250. It worked well as far as restraining the camper. I removed because the bed mounted anchor plates (ears) were flexing and was crushing the bed. The HJ system had the inside cross bar but did not have the additional hardware bolting thru floor, though that would not have stopped ears from flexing.
Changing systems, Whether it will solve issues your having unknown. From past threads movement was a concern, the HJ inside bumpers may help as well as the different angles of the tie downs. From what Im gathering though bed mounted guides may help more to restrain camper.
But to clarify and counter some of the comments, on your 01 Ford specifically, the HJ system by no stretch of the imagination can be construed as a frame mount system. Though that was not the question, just not sure why the references. Yes there are 2 small pieces of bent flat bar bolted between bed wall bracket and floor. A 5" carriage bolt goes thru floor and bed cross member. It does NOT attach to frame or frame component on the Ford.
http://www.happijac.com/images/pdfs/TieDowns/1-ft-ut9.pdf. Installation instruction.
The primary resistance to any force IS on the bed wall mounted anchor plates. That's how its made. Its a proven system thats worked for years.
If you were to change to the HJ system I would consider continue using rear frame mounts. If you do use the bumper buttons install the optional bumper braces, they will help. Likly not on your 01.