I'm kinda on the fence on this one.
I started on acoustic too, and it definitely helped strengthen my fingers.
However, it also stalled my advancement because when I wanted to move into leads and barre chords, I was stuck not being able to do it.
I'd probably say get both if you can afford it.
If not though, once you've mastered the basic open chords, it's time to move on to an electric if that's where your interests lie.