damn, spaced for a bit there and missed the fact that they were laptops, sorry about that, ignore my last post.
Since its a laptop i would go for the 5730 with the slightly less nice screen since you wont be able to swap the GPU. The 5730 will perform a fair bit better than the 4670 but one main advantage is it will be lower power so you will get better battery life out of it.
It will last you longer as a gaming laptop. The HD 4670 is a bit weaker than the the HD 5730. The HD 5730 comes with a "normal" screen, but will last you longers. The HD 4670 comes with a "nice screen", but you're gonna wanna upgrade soon rather than later so that "nice, shiny" screen will not be with you for a while.
If possible and if available, upgrade the HD 5730 to something a bit higher. It may cost an extra $100 or so, but it will give you extra time to save up money for your next gaming laptop (or desktop).