I, personally, would go with the PC version.
2 reasons: 1: I don't have a Wii and 2: it's better, in my opinion.
The Wii version had to be massivly compressed to use on the Wii. However, all the episodes may not fit on there with other games or stuff like that. Your best bet to get it on the Wii is to buy an SD card or something and save the games on there for now. (As far as I know, you can't play games off of an SD, so you'll have to decide what goes where.) The only main advantage I see for the Wii is the WiiConnect24 usage on the game.
The PC version is uncompressed after you install it. From there, it's just about the same as the Wii except no WiiConnect24. In retrospect, the movment will be easier to use with the mouse and whatnot. And, on a PC you can store as much as 60,70,80,100 gigabytes can hold. The game might run a tad choppier/smoother (depending on how great your computer is) and the graphics might be a bit better.
In my opinion, I would have to go with the PC version, even if I had a Wii. But your choice is yours. Not mine.