IT'S TOO BAD YOU'RE NOT ENTHUSIASTIC!!!
LOL.
I talked to an endurance pal as I am not very knowledgeable about this event, so most of this comes from her. According to her, she's one of the best in the sport....JUUUUUST kidding, lol.
It's kind of hard to say as you're wanting a lot of traits in one individual, and some of the things - doesn't eat a lot, doesn't get sick, fast, carry a big person....that, as horse people say, 'that is God's horse'.
You won't find all of that. You'll need to provide feed for your horse on endurance rides, and you'll need to take good care of your horse and condition it very, very carefully, and consistently, to keep it from becoming lame, there is no breed that 'doesn't tend to go lame'. It's a matter of how carefully the horse is trained and ridden, appropriate shoeing. And you will find out that 'going really fast!' is not all that easy in endurance. The horse has to be very, very carefully conditioned, and it takes an awful lot of practice and experience to get a feel for the pace and pick the right gait, and work the terrain into the ride strategically.
Most of the top competitive endurance horses are Arabians. As you go down from the top level competitions, you start to see more variety of breeds. Many people seem to simply do endurance riding, training and competing with 'what they got'. You do see some rather heavily built breeds in endurance in some of the shorter rides (shorter being relative!!!).
Arabians tend to run rather small, and most of them aren't 'up to weight', meaning, built for carrying a heavy rider. My vet had some very angry words about that...and he feels that for endurance the rider's weight should be carefully matched to the size and weight of the horse. They can also be rather sensitive, not always a good choice for a novice.
Actually, the endurance riders here will have ideas, but I seriously think that for a novice rider, whether it's for endurance or not, it should be a quiet, easy to ride horse, that the novice can get experience on, that is up to weight.
Buying a horse that has already done some short rides, and seen all that and done all that and is very reliable and safe, is a really hood choice. I woudn't be as concerned about 'fast fast fast' for a first horse.