There are several different materials that can fit the description of "gravel". Everything from pea gravel, to bank run, to CR-6 (bluestone).
No too sure what you mean by really really long. If you're out there on a ten degree day shovling snow, 100 feet can be really really long.
The type of material you want to use depends on how good the base is that you're putting it on. Staty away from pea gravel or any smooth washed gravel. It will squash from under the tires of vehicles and never will bond together. At my home, my drive is about 600 feet long. I have had bankrum gravel down for about two years. This is a great base, but not a good final topping for the drive. I holds up well, compacts well, but tends to have a "clayey" look to it and does track the redish-orange dirt-especially when the dogs go up and down the drive then walk on the carpets...
If you already have base established, I would recomment topping it with 1 to 2 inches of reclaimed asphalt-AKA millings. This makes for a great topping that locks together and doesn't have the tracking problems of bankrun. I also think it is better that CR-6 becuase it is crushed smaller, locks together better and isn't tough on the bare feet. It's about as close as you can get to asphalt at a fraction of the cost.
As far as doing it yourself. Not trying to take anything away from you, your physcial abilities or the like, but if you are asking the question about what gravel would be best, I would guess that you don't have the equipment necessary to do the job right. If you don't have a bobcat and a roller, you're going to loose the battle. Call some contractors and you'll save yourself a lot of pain and frustration. And it will likely only cost you a bit more to have them do it right versus trucking the material and just dropping it.