I always loved the DT200R but I've never seen one, I found the DT125R is very quick to get hot during any serious off-road riding so I think the twin radiators of the 200 would make it a much better bike. Take good care of these as they almost never come up for sale, spraying lots of WD40 over them after washing stops the fins from corroding.

One modification I would consider to the DT200R would be to protect the aluminium swingarm from the mud flap behind the shock rubbing on it and wearing it away over time (on the rear of the linkage bearing housing). The aluminium swingarm on the 200 is much lighter than the 125's steel arm but bikes with alloy swingarms are prone to this. On modern KTMs a lot of people glue a coin onto the area where it rubs; I used a piece of plastic cut to the right shape and zip-tied on, it doesn't need to be anything expensive or complicated just as long as the aluminium is protected.

That sounds like great fun, I look forward to here more about what you get up to

I think the 200R would make for a nice upgrade