I will be using the corvette trans. The newer tr6060 is the way to go for high hp.
You can bolt a camaro bellhousing to the corvette trans since they are the same gear box. This would eliminate the torque tube issue. Also rockland gear sells their own bellhousing for the tr6060 as well. Only issue that you've noticed would be the length of the setup. Your differential will be way in the rear of the engine bay... I'm putting my trans in the tunnel as lamborghini designed the car. Then bolt a drop box (similar to a v-drive) directly to the rear of the trans where the differential originally bolted. Another issue will be the trans main shaft. The corvette shaft is way to long but the shorter Camaro main shaft interchanges. The stock 27 spline is only good to 500hp, so upgrade to a billet shaft if you plan to go above that.
I'm not sure why most people are scared to try anything besides transaxle's. Or insist it's the way the replicas should be done.
RPM transmissions is building mine. It will handle 800hp/800tq, and a heck of a lot cheaper than a transaxle with the same ability.