I suspect that SR40's are pretty thin on the ground and people overlanding them even thinner, but on the face of it it doesn't look too bad if you're considering the minimalist approach.
The engine is the ubiquitous DRZ400 Suzuki lump and there is a world of long distance feedback about these available, with most of it seeming to be favourable. "Touring Ted" is currently en route to South Africa on a DRZ and if anything goes wrong with it I suspect we'll hear fairly rapidly!
I love to hear how you've solved the fuel and luggage problems. As you've probably discovered, aftermarket bits for CCMs are non existant.