Well if you are going to get a Beginning Gundam I'd suggest the G 30th version out of the 4:
You get the original G version parts in the G30th plus all the nice extras and effect parts. The D and J versions are fine but is an after thought and contains lots of stickers. All the blue and red on each are stickers.
The only other one's I recommend from the same series are Bearguy and Zaku F2000. They are both great kits and look boss.