it means it will be like real solo mining
No it is not "like a real" solo mining because it is a "real" solo mining.
who will mine that block first will get the whole bet amount there
You misunderstood again, you are really mining as of solo mining, and
you dont get the whole bet but instead you got the whole BTC in one bitcoin block if you manage to find a block before the rental runs out of funds
with 99.99% risk.
Not really, as it has been described at the site and also due to the nature of mining, the more hashes you got, the higher your chance to get the block, of course there is a luck factor on it too