One of the problems with these arguments is that the assumption that you need to simulate the entire universe is flawed. All you need to do is simulate me.... All the inputs that go/went into my brain (or whoever), which must be limited. If you can simulate one 'conciousness' in a 'tin' you can simulate an uncountable number (over time, in the future, now(?)), And you needn't do a full life... All you need to simulate is NOW and the memories which make up NOW.
So, if you believe this is possible, and that it is very likely to happen, the likelihood is that you, now, are a simulation, and that I don't exist...