p_m, I gotta tell ya - that is one sweet build you got going on. Worn out many shoehorns so far?
I really, really like what you are doing. Heck, make a couple sheetmetal "wings" lined with thin eggcrate foam to shroud the sides, run your exhaust under and point the tip down behind the basket, and that will be one stealthy machine. If you are worried about airflow, do what I've seen done once - hook up a couple of large computer case cooling fans in a shaped shroud just in front of the seat tube, with the wings in place it will guide all of the airflow over the engine, and the larger fans will move a LOT of air at (typically) just a few volts.
Of course, that assumes stealth is at all an issue for you.