I can't speak for the SportCruiser - having no personal experience of one.
Glass vs Classic Instruments:
If you have an idea of what you are likely to fly once you have your PPL then it would make sense to go for that.
As far as switching between Glass and Classic there is no requirement for any differences training. Until you have a reasonable amount of experience, in different aircraft, I would strongly recommend you get a check flight with an appropriate check pilot (not necessarily an instructor) prior to flying anything which differs from what you are used to.
C172 vs PA28:
You will probably find the C172 easier - mainly due to the better view down (certainly makes the NAV easier). For that reason I would personally learn in the PA28 - as the army say "Train hard, Fight easy".
OC619