welcome to the site!
I wouldn't think that they would do any type of COPO stuff for the new 5th gen. Seems all auto companies think they know what the customer wants these days. Like if you buy an upgraded stereo, then you have to have leather...or something like that. I would love to be able to get one even without the motor and just build an LSX for it, but there is no chance for that. Don't worry, i'm sure the options for this car will be fine, plus if you go with a V8 you'll have too much fun flooring it to not even think about anything else.
Plus, the aftermarket has taken notice to the attention this car has received, so there will be more then enough things for you to buy from other companies out there