Hi,
You are correct, there is only one set of computer tests. Yes, you do get a practise run.
I doubt any other tests will be included into the second day. I have received my sim invite and I've seen the schedule for the sim assessment day and there is no room for any computer based testing.
The software program you are talking about is to expensive in my opinion but it does allow you to practise! You now only need one aspect of that package which makes it even more expensive in relation to the functions you will be practicing. But I also agree that any practise is good practise.
Good luck!!