Like the ones Troy makes. They have quite a few that are like what you just described.Sure does change the look doesn't it. I am not a big fan of quad rails but that looks pretty nice. I particularly like the way the top rail looks. Basically gives it a monolithic look. I might see about something similar with just the top rail and leave it round on the rest.
The Hardest part was getting the barrel nut off. I used a DPMS wrench and I drilled a hole in some wood and clamped the barrel. I barely managed to get it apart. I do suggest getting a upper vise block, I wish I had one.I like it, I have a delton midlenght and put a 2 piece quad on it (didn't want to mess with the front sight/gas block.
How hard was it to pull the gas block and install the new one?