Agree the best way will be to try some of these films and see what you can do with them. They will take some practice and experimentation though (as will any film/developer combo) so if you want to experiment with a few different films like ATP, CMS etc you'll have to do more than a few rolls if you want to really compare them. Particularly with these high contrast films, there are lots of ways to develop them, get different curves etc, so don't be discouraged if the first several rolls are a bust. If ATP is similar to Tech Pan it will probably be a little easier to use than CMS20.

Regarding drum scanning, I can't help you there. I'm a darkroom printer and have zero experience/knowledge when it comes to scanning - particularly high quality drum scanning. You might want to give Photo Service a call since they have a lab that does work for pro photographers. I don't know if they do drum scanning per se but they could probably point you to the right places to get it done properly.