I dont think that learning on a Sb kills your style, because I did

and I still believe that it is the best way to start if you want to shortboard in the future anyway.
and it is very possible to succeed this way, if you got the physical ability. Sure, if you're a weak paddler and in trouble with everything, you should go for a minimal... But longboards are for longboarders, I like the style and it's fun, but no option for me (concerning the way i like to surf and the fact that i have to travel to waves).
I started with a real narrow shortboard and got my first wave on the first day...yeah it was only a 3 or 6 sec ride but hey, thats enough to get hooked.
I tried a longboard last summer and felt more like being pushed around by the waves and hardly getting out.. so what they say about paddling a shortboard maybe true but its even harder to get a real longboard to the lineup on a big day than the narrowest pro potato.