Greg Coleman' 1991 Yugo is a the only Yugo that shows up on EV album but he has a lot of info and over 13,000 miles on his conversion.
The motor I have in my electric car is rated for 6hp (5kw) and is more or less a golf cart motor as well, but if you push it hard while going up a hill I've seen it draw nearly 50,000 watts, so I don't see 4 7kw motors being able to do the same amount of work, I would stick with the golf cart motor, maybe upgrade to a slightly large one if you can and add some cooling to it.
I also would stay away from Gel batteries, our local EV club has had a handful of members use Lead Gel batteries and found them to be very short lived and disappointing flooded deep cycle lead acid batteries seem to give the best performance.
Other then that take a look around at the
EV Photo Album: Our Electric Cars on the Web and see what other cars that are the size of yours can do.