Can you please elaborate on the resources in space? There is better solar energy but what else? I intuitively would have expected resources to be far better on Mars.
The huge theoretical bottleneck on life is energy. This is the only one you need to "expend" on some way, any other resource you just need "enough".
But for the others, with just a reasonably low delta-v and some patience you can get into cubic kilometers of unclaimed raw resources for extending your habitat. You just have to know how to use them (what we currently don't).
You'll certainly get a bigger density of material resources on any planet, but then you will be trapped inside a gravitational wheel and must spend all that delta-v again to break free from it once it's completely claimed. For the short term (to the point that any timeframe is "short" in this discussion) small moons and big asteroids are probably the best places to colonize.
