I wear a size 18 wedding band , have winter gloves custom made. I am 6 foot 8 inches and weigh 450 lbs. What works for me best in my experience is usually proportionate to my size.
While not as big as you, I am a big guy with larger than normal hands. I find that its not the blade length I need to be concerned with, but the
handle length. For most of my outdoor cutting chores, I find a knife in the 4.0-4.5 inch range ideal, as long as the handle is closer to 5.0 inches. This gives me plenty of grip and leverage for when I need it and is generally more comfortable to use.
Personally, for a do-all, survival knife I proably would not go much over 6 inches in blade length. Longer than that is just too long for many taskes (some people
will disagree, but that's my opinion). Given that, I would consider the
ESEE-6 to be an excellent choice for a "survival" knife. Its a tough, quality knife with a good sized grip and is well within your price range.
If you are still convinced that you really need a bigger knive, my choice would probably be the
ESEE Junglas from the same maker. Its an even larger knife, with a handle amost 6 inches long, and a blade of approximatly 10 inches.