Damn Mark.. you make me want to hop a plane and visit my friends in AZ...and aim to bump into you while there.
Bonne has all the gadgets and goodies. GP's didn't. Your Ei had air shocks and could easily handle drag bags to keep weight transfer to a minimum. GP's.. nope, enjoy staring at the sky when you touch the throttle. Comfort, feeling that you have room in the cabin etc...it's all Bonne. The last generation of GP is much better than say the 97-03... but it was never designed to be an equal to Excitement with Attitude.
Ask any GP driver at the track if they can pump up their own tires after letting some air out... nope
Since you enjoy a serious build. A Bonne GXP had the Deathstar motor and the coveted 4T80 trans. If you look around, you'll see a thread or two where the GP guys would love to use a 4T80 to hold power. The 4T65 doesn't usually hold up to a lot of abuse (I know this from experience). Without too much hardship you can easily mate a 4T80 to an SC motor in a Bonne. Soon enough there will be a way to control it. Poof.. all set. Build that 3.8 as crazy as you'd want and the trans should hold.