I may be a little late on the ball here but:
If you're training alone at home resistance bands might be the better choice because:
- Don't need a spotter, not as dangerous as weights which simply react to gravity. The bands will stop 'resisting' when you stop stretching.
- Easier to store around the house.
- May be more cost-effective than a full blow weight set (resistance bands with 40-50Kg weight ratings are likely to be cheaper than buying a barbell with plates equalling 50Kg).
As for the leg press - doing a resistance band squat should be similar, the only problem is they only provide resistance when the band is stretched, so when you're in the bottom position, they don't offer much resistance so it is a little erratic. The squat is also a little more unstable exercise than any machine exercise.
Overall if you're just going for the home gym, resistance bands are the best - you can also perform calisthenics exercises but to a more difficult degree with them.