A 1000 W motor is only 1.25 HP, or there abouts. Now assuming you're about like the guy in the picture (or myself) add another 200 for driver, another 200 for batteries (assuming 4 x 12v, around 50 lbs each, could be lighter). That's an estimated 700 lbs. Now I don't have a great feel for HP, but one horse trying to pull 700 lbs doesn't sound like a good time. You said max speed wasn't important, but I'd say it'd just nudge along. I'd probably recommend a slightly larger motor, maybe a 2 or 3 hp like one of these (full disclosure: KTA is a site sponsor, but I've never bought form them and don't have any association with them)
http://store.kta-ev.com/dcmotors.aspx