Hey Colin,
I think you can go into the extreme on this one and work with a user parameter field
then every formule or everything you want to "custom" display in a CASE formula
CASE user1: ....
CASE user2: ....
would be a HELL of a lot of work the first time but if you can make a global template that u can use in all your reports it should work i guess
good luck with it !!
Adam