Get the 2008 or the 2010.
2008 was the last year of marzocchi forks on the old style frame, for 2009 they went to the sachs fork which alot of people had issues with in stock form, Les at LTRacing can sort out the sachs though.
The 2010 came with a much better stock fork set up on the sachs.
If your going used get an 07 or newer, they come with the new subframe.
The 200 has never shared a frame with the 125, that MXA article is wrong, the 200 shares a frame and most engine components with the 250/300. The 125 has the same geometry as the bigger bikes but has a much smaller engine cradle.