What a great machine, they're becoming rarer and hard to find in unmolested condition, so definitely bear that in mind before tou do anything drastic and keep all the original parts.

I super moto'd my DTRE using Yamaha WR450F Forks and Aprilia RS125 wheels just because.

But the simplest way, to my knowledge, using the stock DT200R would be to grab the DTX setup as that should be a drop in replacement, may need to machine up some rear spacers for the swinging arm, or just grab a DTR rear swinging arm.

If your bike uses the ally arm then it's just easier to get spacers made. PCBWay will make them for £40 no dramas at all.

Sounds great though, I always wanted a DT230 Lanza personally.