Putting aside the entry cost, which is, um, immodest, Keihin FCR 35 mms will give you umatched performance, from idle to flat out, and deliver great mileage (50+ MPG - I got an indicated 62 MPG recently after extended 50-70 MPH running, albeit my odo thinks I'm running a 19" tire, whereas it's 18", so reduce that by 5% or so).
They're mechanically linked, so no synchronization problems. (But as an airhead owner, I'm aware of the importance of synchronzation but have to ask - is it that hard? No. Get a TwinMax or a $4 mercury tube setup and use it.)
Again, the entry cost for the FCRs is not inconsiderable. But I defy you to come up with a carb or carbs that compares on performance.