did you buy heaters for the reception?

hey all!  

I know this is getting "last minute" but I'm having my wedding September 24th (this year!). I live in Montana, which means weather is iffy... but usually September is actually one of our best/warmest months. We're planning on having an outdoor reception, which isn't that uncommon here, but I've also been to plenty of fall wedding receptions where I was uncomfortably chilly some of the evening. I don't want to put my guests through that in case it cools off too much, so I've been thinking of getting some outside heaters -- the patio type that people stand around. We don't carry them in Montana so I'm trying to find some online. Has anyone else done this? Where did you buy yours? I need help!! My top pick so far Patio Heater.  Thanks for your input guys!