I have recently purchased a TTR250 that has already been heavily modified by the previous owner. Only thing thats missing to make it a small adventure bike is a rack system. I have found this on ebay but it is for a raid model.
That looks a really nice rack. Unfortunately the subframes are slightly different between the OE and Raid as noted in the FAQs section, and the passenger footpeg mounts and rear diagonals are different. However, the basic shape and layout is more or less the same, and I think it would be worth buying and doing the required mods to make it fit rather than starting with something like the bboffroad rack which is too narrow and will need saddlebag supports making from scratch.
If I lived a bit nearer to you I'd offer to do the work, but the flight's a bit expensive!
Good luck,
Simon.
