So, an update, after having 2 inches of water in the sub-basement this morning (yay!) I went for option 2 to start with, so far I've jsut replaced the pump, got a Rigid pump with a float that goes up and down a pole, vs the free float, seems to work fine, and has drained the majority of the water out (thank goodness).
The problem that I can see, is that because the Basin is quite small, it's cycling quite a bit (and that's the problem with the fixed float, it doesn't move very far) I'm assuming a bigger basin would HELP resolve this issue, in that it would allow more volume of water to accumulate before the pump will get triggered, so that's going to be the next purchase.
One thing I'm still struggling with, most sump basins seem to have quite a large hole in one side, why is this? Idealy, I would have thought, I need a solid basin and then drill a bunch of holes around the sides (smaller holes) to allow water in, but not the gravel that I intend to put in the surrounding area, am I totally off base?