Also to clarify, my goals are get top speed up to 160mph, and at least double the tank size. I plan on ripping out the storage in the back and replacing with a new tank.
re top speed , good luck , brave man
re tank - are you planning removing the existing panniers and fitting a single tank in the luggage space , or having all three?
To save weight I would be going with just a new central one though I doubt you will get the capacity of the panniers. Very interesting non the less. I can imagine a large motorbike tank directly under the existing filler and keeping the existing clam shell boot lid to hide it which would save weight ( i am presuming those existing tanks are heavy ) and make useful room around the bevel box for maintenance etc