I agree with Dustin. A working pack is a good pack. Even though, after I made my first, I had already made a new one before I had a second chance to use the first. So I know how you feel on trying to perfect it.
I have made the G4 before, and it is a great pattern, but it is massive. I can't fill it now unless I roll a full length CCF pad in it vertically to fill up some space just because my other gear has become so low volume.
I haven't tried any of the other suggested patterns or kits, but they all look very nice.
I am working on my newest backpack right now and will be preparing a guide to go along with it on my blog. I plan to have it done before the new year, maybe sooner. It should give a lot of options, like a wrap around hipbelt that is removable, a removable framesheet, easy ways to scale it to different sizes and a, hopefully, overall simple design.