Thanks for the welcome!!
The pony I relate most to is Twilight, but Pinkie really cracks me up all the time! I don't know how many early generation ponies I'll get into, but collecting at least every iteration of Twilight and the FiM characters might just have to be a goal of mine! Apple Jack is another favorite!
I'm new to pony collecting, so I'm not sure how much is out there. But that's the thing I like about collecting - learning the history of it all. And with this community I think I'll have a lot of fun learning!