Advice on eliptical to get?

I want advice on which eliptical machine to get. I will buy used, but I want one that goes in the circular motion not back and forth. I'm mostly worried about a smooth movement. It's triple digits here and I cant take my little ones out in the heat just so I can work out. I try to get up at 6 a.m. to walk but with a newborn that just isnt happening. TIA.