I've thought about the new coupe, and if I ever go with an auto, I'd go with a TH400. One call to JW gets you an Ultra Bell that is SFI approved and allows you to bolt the tranny right to your block, as well as an Ultra Wheel that is also SFI approved and has provisions for ford and GM converters. The C4's are just too damned expensive to live behind any type of HP, and they all have the 2-3 flare, which is not curable, and will eventually burn up high gear in ANY application.
So if you want a 3 speed, I'd consider a TH400.
As far as the glide, I'm not so sure you're making enough HP to NOT need a 1st gear, plus your car is still pretty heavy. Remember the Street Outlaw guys used to run C4's at 1000 HP. If the launch is too violent for your chassis, leave at a lower RPM or limit boost at launch, don't lose 1st gear altogther.