I chuckle when I hear about the -55 being a bumper helmet. It is tested to 400G's. The human body can only withstand about 100G's of instantaneous impact before things like organs start smashing around inside your body. How much protection from instantaneous G force is enough? If you're heart is going to bust by smashing into your rib cage in the lower ranges, do you really need the 500G, 800G, or 1000G head protection? To each his/her own though....
Heli vs fixed wing -- the only difference is some additional lateral protection. Helicopters tend to roll, where as fixed wing do not, due to the wings sticking out. They tend to flip. I think a heli helmet in a fixed wing environment is just additional un-necessary weight.
The Gallet's are certainly a lighter helmet. I have never really noticed my gentex helmet being "heavy". When you compare the two, you can tell that the Gallet is much lighter.
As for ANR vs CEP. I think you will find that the extra wires from the CEP's a pain in the rear end. You will be taking off your lid multiple times per day. It is just one more thing to unplug before you actually get your helmet off. I know of a couple guys that have CEP's and they end up wandering around with the helmets on because it is too much of a process to unplug. They do swear by them though, so maybe they're on to something?
Do not get custom molds. The helmet will be too tight once your start to warm up.
Stay away from webbed helmets like SPH's in my opinion. Some guys love them for breath-ability. I find when you turn your head quickly, the helmet stays put and there is too much slop.
Make sure your helmet has a small pig tale single point connection. Make sure your wire from the aircraft inputs to the female single point connection are long. Make sure your ANR cable is long. I ended up buying an extension. Don't bother with bayonet attachments.
There is some more food for thought to make your decision even more difficult. It's only over a couple grand....no big deal

--Air to Ground Chemical Transfer Technician turned 4 Bar Switch Flicker and Flap Operator--