This is a toy question - Because I know some of you know :)

We've seen those mechanical sex machines that have a dildo and use an electric motor to make the dildo go in and out. I'm looking for one while my wife is gone in a few weeks. I want to ride/be railed for one - all the bottom fun without the complications of hooking up. Does anyone have any suggestions? I'd prefer one that's cheaper but has a long stroke length.