I had thought about a 'Busa set up at one time.  The cost is what turned me off finally.  For the price that you pay for a engine, harness etc... you can buy a complete liter bike.  Whos know, maybe one day I will play with one. 
Really liking my 1100 set up.  Seems bullet proof.  Really looking forward to the new build we are starting too!!!  It's gonna be fun to build.