I would suggest that you attend the Open days run by the uni's, that way you can get a feel for the place and the possible course. You should also be able to find out what the uni's require from you to be offered a place.
The access course is still fairly new, most last year were only vaguely aware of it, but I imagine this year they will have a better idea what they require. Armed with better information, you should be able to make more informed and realistic decisions.