I'll probably borrow a pc copy from a friend after a few play-throughs on my xbox. The reason being is i would like to stay away from mods until i have fully enjoyed the game. This is only because i tend to lean towards mods if i have the ability, and some mods can truely ruin the experience. If i don't have the ability to mod, i will experience the game for what it is. After that, i will trade with my friend, and go mod crazy.
In terms of what you should do, idk do what seems right. If you have the money for a new pc, make sure your buying it for more than just Skyrim.
You know, Willpower exists in real life, too, and not only as a TES attribute...
Besides, there won't be many mods out in the first months, and the ones which will be are going to be mostly quick fixes, or stat changers (many of them ridiculously overpowered). I don't plan to install ANY mod for at least my first full playthough, and I don't have even to try not to do it, because although I'm a mod-addict, I absolutely don't want to spoil my first Skyrim experience.
But by first playing 360/PS3, you're going to miss quick bugfixes, which are always much quicker than official patches. It's a pity IMO...