Hi Wazza,
Even though I started on an "Organ (L100)" If your going to learn "Piano" then it should be done with a piano for all of the reasons stated. However, IMO , it can`t hurt mess`n around with a keyboard from time to time As long as you "stick" with your lessons. The piano is a great way to learn to compose and IMO the basic instrument (along with the Guitar, of course)
O-BTW, "Welcome to our family and the best corner of the web" everyone here is a BIG help so post if you need us (or just to keep in touch) !!
jedi