Are there any arduinos I can program with Pythonista?
Not in the current 1.5 version of Pythonista, there would be no way to communicate with them. (As far as I know Arduinos don't have wi-fi support.) In the upcoming 1.6 release it might be possible to use the
cbmodule to communicate via Bluetooth LE, if Arduinos support that.
(There's also no way to program an Arduino directly and only using Pythonista. They might support Python, but you'd still need a real computer to write the Arduino side of things.)