have you already considered going mc21.

I ride an mc16 so don't what to put you off but how much of the mc21 do you have and wouldn't it be better flogging all the mc16 bits for an mc21 engine. you'd probably get a track day nail with enough bits to get you going and since you don't seem affraid to get your hands dirty, why not

swaping an engine over for different models i would of thought the biggest problem is the electronics. if you are intending on putting the mc16 engine in, isn't it going to be an under powered bike as from what i have seen the mc16 can't produce anywhere near the power you might want. i mean it'd be like putting a 1992 cbr600 engine in a 2001 fireblade i.e. both very nice but the conversion should be the other way around.

however, i'm not knowledgable about these bikes so maybe someone else has tried it might not share my opinion.

good luck anyway, looks like your going to have hours of enjoyment which ever way you go.