Hmm, without giving away anything; I thought there were "main" dragons and then those that simply randomly spawn wherever? Are you saying NO dragons start spawning until you hit a quest trigger?
Anyway, unless you are banking on texture packs being released in the next month or so, just get it for the 360/PS3. So many people are raging over how awful the textures look on ultra on the PC. It really does not look much better than the console at all, and that's with AF/AA etc enabled.
You also cannot use hotkeys, and have to use a mouse/keyboard with an interface that was specifically designed for the console. At least with Oblivion you could map quickslots, but you simply cannot with Skyrim. That's kind of pathetic really.
One that you can constantly choke and revive?