I took my 30 degree EE Revelation with 10D shell and liner out for the first time last week. It weighs 19.93 ounces in the 6'6" wide size. Between the 12.8 ounces of down and the 2.5+ inches of loft I would say this is a 25 degree quilt easy. I would consider a custom sized Revelation if I were you, at 6'4" I find the EE 6'6" length barely adequate so I would add 2-4" in length if I were your height. I am very broad shouldered and find the 58" top width just fine. I have a custom 60" wide Revelation X as well and didn't miss the extra width.
Re. Hammock Gear, I briefly had a wide/long Burrow, and it was not nearly wide or long enough. You would need a custom extra wide extra long size from them. The weight would probably be comparable though, I suspect you will find that custom offerings from EE, Zpacks and Hammock Gear to all be within an ounce or so of each other with comparable dimensions and amounts of fill.