Which Android In app Purchase plugin should I choose?

Checking Prime31's website i found out that they have 3 plugins available being: Google In App Billing, MoVend and Aarki. I think my choice would be MoVend since it seems like the only one that provide both Google and Amazone purchases. But what are the differences between these 3 plugins? What is the difference between Google In App Billing with MoVend's google setup? etc..

Would rly appreciate some insight from other users of Andoid In App purchases plugins.